In this blog post, Nandini Mukati, a student of the School of Law, Forensic Justice and Policy Studies, National Forensic Sciences University, Gandhinagar, writes about the father of International Law: Hugo Grotius. This is an exhaustive article which deals with the concept of International Law, its history and relevance.

This article has been published by Sneha Mahawar.


Relations between independent states are governed by international law. The norms of law that bind states are derived from their own free will, as represented in conventions or usages widely regarded as articulating legal principles and formed to control the relations between these coexisting separate communities or to achieve common goals. As a result, restrictions on state independence cannot be assumed.

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Because norms give order and serve to limit damaging conflict, international law arose as a result of an effort to deal with conflict among states. International law reflects the creation and subsequent adjustment of a world order based almost entirely on the concept that independent sovereign states are the only actors in the international system that matter.

Today, every individual has rights that pervade the international community and are profoundly enshrined in an imperfect global law that, in turn, pervades each of our lives. This rule isn’t set in stone; it’s evolving all the time. To realise its emancipatory potential, it must be made effective, challenged, defended, and reinvented.

We will cover the beginnings of international law, Hugo Grotius’ contribution, how international law has evolved in the twentieth century, the sources and theories of international law, and the individualization of international law in this article. Finally, we look at some of the most recent international law objections.

Father of International Law : Hugo Grotius

Hugo Grotius was a Dutch jurist and scholar who lived from April 10, 1583, in Delft, Netherlands, to August 28, 1645, in Rostock, Mecklenburg-Schwerin. His masterpiece, De Jure Belli ac Pacis (1625; On the Law of War and Peace), is regarded as one of the most important contributions to the development of international law. Grotius, who was also a statesman and diplomat, has been dubbed the “Father of International Law.”

Hugo Grotius was the first child of Jan de Groot and Alida van Overschie, and was born in Delft during the Dutch Revolt. His father was a man of intelligence and political significance, having studied under the great Justus Lipsius at Leiden University. His forefathers had played a significant part in local administration since the thirteenth century, earning him the title of Delft patrician.

Hugo Grotius was an exceptionally gifted child who began writing Latin ballads at the age of eight and entered the arts faculty at Leiden University at the age of eleven. Grotius studied under the renowned humanist Joseph Scaliger, who was essential in Grotius’ growth as a philologist. He traveled to France with Johann van Oldenbarnevelt, a famous Dutch statesman, in 1598, and visited Henry IV, who dubbed Grotius the “wonder of Holland.” Pontifex Romanus (1598), which has six monologues on the contemporary political situation, reflects this perspective. 

In 1599, he established himself as an advocate in The Hague, temporarily residing with the court preacher and theologian Johannes Uyttenbogaert.

The Netherlands commissioned an account of the United Provinces’ insurrection against Spain from Grotius in 1601. In 1604, he became involved in the legal processes following the seizure of a Portuguese carrack and its cargo in the Singapore Strait by Dutch traders. This was his first opportunity to write methodically on themes of international justice. Grotius attempted to justify the seizure by appealing to natural justice considerations. He’d cast a much wider net here than just the issue at hand; he was interested in the source and foundation of war’s legality in general. The treatise was never published in its entirety during Grotius’ lifetime, possibly because the company’s victory in court negated the need for public support. In 1608, he married Maria van Reigersberch, through whom he had three daughters and four sons (four of whom lived to adulthood) and who would be important in assisting him and his family in surviving the coming storm. Grotius’ political career was aided by his continuous affiliation with Van Oldenbarnevelt, who maintained him as Oldenbarnevelt’s resident advisor in 1605, Advocate General of the Fisc of Holland, Zeeland, and Friesland in 1607, and then as Pensionary of Rotterdam (the equivalent of a mayor) in 1613.

The resulting work was written in the style of Tacitus, a Roman historian, and covered the years 1559 to 1609. Despite the fact that it was nearly done by 1612, Annales et Historiae de Rebus Belgicis (“Annals and Histories of the Low Countries”) was only published posthumously in 1657. When Middelburg professor Antonius Walaeus produced Het Ampt der Kerckendienaren in late 1615 (a reaction to Johannes Wtenbogaert’s 1610 Tractaat van ‘t Ampt ende autoriteit eener hooger Christelijcke overheid in kerckelijkcke zaken), he sent a copy to Grotius out of goodwill. This was a moderate counter-remonstrant book “on the connection between ecclesiastical and secular administration.” In early 1616, Grotius received a 36-page letter from his friend Gerardus Vossius advocating a dissenting viewpoint, Dissertatio epistolica de Iure magistratus in rebus ecclesiasticis.

Grotius was extensively involved in the politics of the Netherlands. The combined kingdoms of Spain and Portugal claimed a monopoly on trade with the East Indies in the early 17th century.

With the help of his wife and maidservant, Elsje van Houwening, Grotius managed to leave the castle in a book chest and go to Paris in 1621. He is primarily remembered in the Netherlands today for his audacious escape. The original book chest is said to be in the collections of both the Rijksmuseum in Amsterdam and the museum Het Prinsenhof in Delft.

From 1621 until 1644, Grotius spent nearly his entire life in France. During his term, Cardinal Richelieu led France under Louis XIII’s rule from 1624 until 1642.

Grotius’ most renowned book, De jure belli ac pacis [On the Law of War and Peace], was dedicated to Louis XIII of France in 1625 and was published in France.

Grotius began work on a treatise that he had originally composed in Dutch verse in jail, presenting elementary but systematic reasons for the reality of Christianity while in Paris. The Latin dissertation, De veritate religionis Christianae, was published in 1627, while the Dutch poem, Bewijs van den waren Godsdienst, was published in 1622.

He attempted to return to Holland in 1631, but the authorities were still hostile to him. In 1632, he relocated to Hamburg. However, he was dispatched to Paris as an ambassador by the Swedes, a European superpower, as early as 1634. He stayed in this role for eleven years, with the objective of negotiating the end of the Thirty Years War for Sweden. During this time, he was interested in Christian unity and produced a number of papers that would later be combined under the title Opera Omnia Theologica.

Following the death of Prince Maurice in 1625, when toleration was granted to them, many exiled Remonstrants returned to the Netherlands. In 1630, they were given entire autonomy over the construction and operation of churches and schools, as well as the right to dwell wherever in Holland. A presbyterial organization was established by the Remonstrants, led by Johannes Wtenbogaert. Grotius joined Episcopius, van Limborch, de Courcelles, and Leclerc in establishing a theological seminary in Amsterdam.

Grotius was appointed ambassador to France by Sweden in 1634. Grotius accepted the offer and moved to Paris, where he stayed until 1645 when he was relieved of his duties.

In 1644, the queen of Sweden, Christine, who had reached adulthood, began to carry out her responsibilities and returned him to Stockholm. He moved to Sweden in the winter of 1644 – 1645 but decided to depart in the summer of 1645 due to the tough conditions.

Grotius was shipwrecked on the journey home from his last visit to Sweden. He washed ashore on the shore of Rostock, ill and weather-beaten, and died on August 28, 1645; his body was finally repatriated to his homeland and buried in the Nieuwe Kerk in Delft.

Grotius wrote in a number of fields throughout his life. He edited the North African poet Martianus Capella’s encyclopaedic book on the seven liberal arts, as well as the Greek astronomer Aratus of Soli’s Phaenomena, with commentary.

Grotius wrote a variety of philological studies as well as a drama, Adamus Exul (1601; Adam in Exile), which the English poet John Milton praised. Grotius also wrote a number of theological and politico-theological writings, including De Veritate Religionis Christianae (1627), which was perhaps his most popular work during his lifetime.

Contributions of Hugo Grotius to International Law

Hugo Grotius is regarded as a prominent figure in the study of international law today. Unfortunately, opinions on the worth of his contribution to the cause of international peace are conflicted. Grotius was able to establish various rational foundations underlying law as a result of his rationalist worldview. Law was derived from principles rather than being imposed from on high. The axioms that agreements must be kept and that injuring someone necessitates restitution were among the founding principles. Much of subsequent international law has been based on these two concepts.

Grotius set out to build a general theory of law (jurisprudentia) that would constrain and govern war between many independent powers, including nations, in order to achieve his practical goal of minimizing bloodshed in wars. Grotius’ legal masterpiece, De Jure Belli ac Pacis, was published in 1625, and it was heavily affected by the terrible, violent political fights that had erupted in his own nation and throughout Europe, particularly the Thirty Years’ War, which had erupted in 1618.

Grotius placed natural law at the centre of his jurisprudentia, following Roman law and the Stoics’ work. He claimed that law derived from man’s intrinsic nature would be valid to some extent. He made this bold claim because he believed that natural law—the most crucial weapon for preventing and regulating conflicts in Europe—must be independent of religion and apply to everyone, regardless of their religious views. He knew, however, that secular law alone would not be sufficient to restrict and regulate war. As a result, he reinstated several Christian themes into his jurisprudentia.

Grotius was frequently reported as saying that law or natural law should be “secularized,” but this was a hypothetical rather than a categorical statement. To comprehend De Jure Belli ac Pacis’ crucial character of law, one must first comprehend the complete structure of his argumentation. To control and regulate both the resort to war and the use of violence in combat, Grotius employs a multilayered network of norms, including a variety of religious ones.

Only righteous wars, according to Grotius, should be authorised. War must be accepted as a means of resolving issues because there is no court for legal resolution between nations. Causes of war, on the other hand, should be limited to those that may be litigated. The defence and restitution of property, for example, are just causes of war (see also just war). He also devised a theory of crime and punishment, which he used to justify wars as just punishment for crimes committed by autonomous forces, including governments.

Grotius articulated the revolutionary notion that the sea was international territory and that all nations were free to exploit it for nautical trade in his book The Free Sea (Mare Liberum, published 1609). Grotius supplied an adequate intellectual basis for the Dutch breaking up of numerous trade monopolies through its powerful naval might by asserting “free seas” (Freedom of the Seas) (and then establishing its own monopoly). [requires citation] The Dominion of the British Sea, or That Which Incompasseth the Isle of Great Britain, is, and Ever Hath Been, a Part or Appendant of the Empire of that Island, England claimed in John Selden’s Mare clausum (The Closed Sea), “That the Dominion of the British Sea, or That Which Incompasseth the Isle of Great Britain, is, and Ever Hath Been, a Part or Appendant of the Empire of that Island.” Although many governments in the Indian Ocean and other Asian seas recognised the right of unrestricted passage even before Grotius wrote his De Jure Praedae (On the Law of Spoils) in the year 1604, it is widely considered that Grotius was the first to advocate the notion of sea freedom. Furthermore, under the ideas of jus gentium, Francisco de Vitoria, a 16th-century Spanish theologian, proposed the idea of maritime freedom in a more elementary form. Grotius’ concept of sea freedom would last until the mid-twentieth century, and it is still used over most of the high seas today, albeit the scope of its application and reach is shifting.

History of International Law 

“Those who ignore history are condemned to repeat it.”

The emergence and development of public international law in both conventions and conceptual understanding is examined in the history of international law. Renaissance Europe gave birth to modern international law, which is closely linked to the evolution of western political organisation in the period. The growth of European concepts of sovereignty and nation-states would entail the establishment of interstate relations methods and norms of behaviour that would provide the groundwork for international law. While the contemporary system of international law may be dated back 400 years, the formation of the concepts and practices that would underpin it can be traced back thousands of years to ancient historical politics and connections.

Around 1000 BC, Ramses II of Egypt and the Hittite monarch signed an agreement establishing “eternal peace and fraternity” between their two nations, which included dealing with territorial respect and forming a defense alliance. Before Alexander the Great, the ancient Greeks created a slew of minor states that interacted continuously. In both peace and war, an inter-state culture arose, dictating how these states should interact. These principles did not apply to relations with non-Greek nations, although the Greek inter-state community mirrored the current international community in certain ways within itself.

A number of variables collided in the 15th century, contributing to the rapid growth of international law into its modern form. The arrival of the printing press, as well as the flood of Greek scholars from the falling Byzantine Empire, fueled the growth of science, humanism, and concepts of individual rights. The increased navigation and exploration by Europeans posed a challenge to scholars in terms of developing a conceptual framework for dealing with various peoples and cultures. The rise of systems of governance like Spain and France brought increased wealth, ambition, and trade, necessitating increasingly complex rules and regulations.

International law can be said to have begun in 1648 with the Treaty of Westphalia, which established sovereign equality among states. The Geneva Conventions of the nineteenth and twentieth centuries formalised rules regulating the conduct of war (jus ad bellum and jus in bello), which were most famously codified in the Geneva Conventions of the nineteenth and twentieth centuries. Organizations arose quickly to aid in the establishment of the law and the resolution of conflicts. The League of Nations attempted but failed to make war illegal. The United Nations has recently emerged as the clearest source of international law. The United Nations Charter establishes the conditions for the lawful use of force, and the United Nations has acted as the primary forum for the development of new international law.

The founding of the International Criminal Court is the most recent development in international law that targets individuals rather than nations. Following an examination of state-oriented courts, these challenges will be addressed.

The International Court of Justice

In order to aid the establishment and preservation of international law, states have built an ever-evolving array of international institutions. The Permanent Court of Arbitration was formed by the Hague Conference in 1899 as an entity to which states might go for dispute resolution. It was a predecessor to the Permanent Court of International Justice, which was established in 1921 following World War I. It was mostly taken from the Treaty of Versailles, and it set the foundation for minority rights protection. The Permanent Court of International Justice (PCIJ) was renamed the International Court of Justice (ICJ) in 1946, and it is still active today.

The International Court of Justice (ICJ) was established as a judicial authority to consider matters involving national-state disputes. It consists of 15 judges who are elected to nine-year terms. The judges are nominated by the Secretary-General and chosen by the United Nations General Assembly and Security Council. All the parties (states) to a dispute must recognise the ICJ’s jurisdiction before it can hear a case. The International Court of Justice (ICJ) remained minor until the 1980s when the Soviet bloc rejected it and Third World countries turned against it following a series of adverse verdicts.

However, once the International Court of Justice (ICJ) decided against the United States in a case brought by Nicaragua over the mining of Nicaraguan waters, it regained credibility, the number of states accepting its authority increased rapidly, and its docket was swamped with cases.

Sources of International Law

The conduct of the 192 countries that make up the international community is essentially decentralised in nature, resulting in international law. The Statute of the international court of justice (ICJ), Article 38 identifies certain sources:-

(a) Treaties between States;

(b) International customary law arising from state practice;

(c) General principles of law acknowledged by civilised states; and, as a secondary manner of determining international law standards;

(d) The publications of “the most highly qualified publicists” and judicial rulings.

A treaty, necessarily, is not so much a source of law as it is a source of legal responsibility. Treaties (sometimes known as agreements, conventions, exchanges of notes, or ordinances) between countries—or between countries and international organizations – are the other major source of law. 

Treaties bind only the states that become parties to them, and the decision to become a party to a treaty is fully up to the state, signing up to a treaty is not required. What makes a treaty binding on the countries that have signed it? The response is that pacta sunt servanda, a tenet of customary international law, requires all states to honour their accords. As a result, treaties are better regarded as legal sources of obligation.

Every treaty in force binds the parties to it, and they must uphold it in good faith (Art. 26). Art. 27 strengthens the rule by stating that no party to a treaty may use its internal law to explain its failure to perform any of its international treaty duties. Pacta sunt servanda is thus perhaps the most fundamental concept of international law, and certainly the most fundamental principle of treaties. When a new state arises as a result of a revolt, it does not believe itself to be bound by the treaties signed by the previous state. When the treaty’s responsibilities pertaining to a portion of the territory that has been ceded or amalgamated with other countries, the concept is also ignored.

The earliest and most original source of international law is international customs. Customary international law laws are those that have evolved through time through a long process of historical development. The formation or development of a custom is a usage that has the force of law but has not yet attained the force of law. Usage is the liminal zone between custom and usage; custom begins where usage ceases. When states behave in a specific way in their international relations under certain circumstances, it is believed that they will behave in the same way under comparable circumstances. However, when this usage is widely accepted and recognised by states in their interactions with one another, a perception emerges that such a habit or behaviour has become the state’s right as well as obligation, and usage becomes the custom.

“The general principles of law acknowledged by civilised states” is the third source of international law identified by the International Court of Justice’s statute. These principles essentially provide a system for dealing with international issues that aren’t currently covered by treaties or enforceable customary standards. Many of these general principles are procedural or evidential principles or those that deal with the machinery of the judicial process, and they can be found in both municipal and international law. As a result, Poland was forced to compensate Germany for the illegal expropriation of a factory in the Chorzow Factory case.

The principle of good faith is perhaps the most essential in international law. It is the cornerstone of treaty law and governs the formulation and fulfilment of legal commitments. Another key fundamental principle is equity, which allows for some flexibility in the interpretation and enforcement of international law. For example, the Law of the Sea Treaty called for the delimitation of exclusive economic zones and continental shelves between governments with opposing or neighbouring coasts on the basis of equality.


Other theorists of International Law

  1. Hans Morgenthau – The unquenchable human craving for power, which he connects with the animus dominandi, or the urge to dominate, is the main source of conflict for him. In the second edition of Politics among Nations, Morgenthau organises realism in international relations around six principles. He claims that realism is founded on objective laws that have their roots in unchanging human nature in the fundamental principle. He aspires to turn realism into a theory of international politics as well as a political art form and a functional tool in foreign policy.

The concept of power, or “interest defined in terms of power,” is the cornerstone of Morgenthau’s realist theory, and it informs his second principle: the assumption that political leaders “think and act in terms of interest defined as power.” Although interest defined as power is a universally legitimate category, and indeed a fundamental aspect of politics, as Morgenthau shows in the third principle, diverse things can be connected with interest or power at different periods and in different circumstances. The political and cultural environment determines its substance and how it is used. Morgenthau addresses the relationship between realism and ethics in the fourth principle. While realists recognize the moral importance of political engagement, they also recognize the conflict between morality and the prerequisites of successful political action, according to him. Political conduct should be guided by caution rather than conviction in one’s own moral or ideological superiority. This is emphasised in Morgenthau’s fifth principle, which highlights the idea that all state actors, including our own, must be viewed exclusively as political entities pursuing their individual power-based purposes. According to Morgenthau’s sixth realism principle, politics is an autonomous realm insofar as power, or interest defined as power, is the notion that constitutes politics. It can’t be put on the back burner for the sake of morality. In politics, however, ethics continues to play a role.

  1. John LockeIn Two Treatises of Government, published in 1689, John Locke outlines many of the principles that are now credited to liberalism. Locke makes observations on society and emphasises the necessity of natural rights and laws in his second treatise. Locke argues that people are born with no preconceived conceptions or ideas. The State of Nature is so named because it depicts people in their most primitive state. People’s experiences begin to shape their attitudes and actions as they mature. They are naturally in the state of nature until they choose not to be, or until their barbarous nature is altered. According to Locke, civil governance can bring order to chaos.
  2. Cornelius van Bynkershoek – Bynker-Shock is the most prominent supporter of positivism. He claimed at the time that the foundations of international law were universally agreed-upon customs and treaties.
  3.  J.G. Starke –  International law is the corpus of law that contains the majority of the principles and rules of conduct that states feel obligated to follow and, as a result, do so in their interactions.
  4. Anzilotti (Italian Jurist) – According to him, international law has binding power because of a basic principle known as Pacta Sunt Servanda. However, the positivist approach fails to account for the binding force of customary international law principles.
  5. Fenwick – International law is a set of laws acknowledged by the entire community of states as establishing their rights and the procedures for enforcing or redressing violations of those rights.
  6. Prof. L Oppenheim – The system of customary and conventional rules that are deemed legally binding on civilised states in their interactions with one another is known as the law of nations in international law.
  7. Philip C Jessup – International law, sometimes known as the law of nations, must be defined as the law that applies to states in their interactions with one another. He goes on to say that international law may also apply to certain inter-relationships between individuals when those inter-relationships affect international issues.
  8. Gray – International law, sometimes known as the law of nations, refers to a set of laws that, by definition, govern the behaviour of states in their interactions with one another.
  9. Hall – International law consists of certain rules of conduct that modern civilised States regard as binding on them in their relations with one another with a force comparable in nature and degree to that which binds a conscientious person to obey his country’s laws, and which they regard as enforceable by appropriate means in the event of an infringement.


Grotius set out to develop a general theory of jurisprudentia that would limit and manage conflict between numerous autonomous forces, including states, in order to achieve his practical goal of reducing wartime bloodshed. The exponential, multifaceted, disorderly, and fragmented evolution of international law reflects the growing complexity of international society and the national societies it controls, and thus the complexity of itself via a feedback effect, in an age marked by political reappraisal of law. We are undergoing a reorganisation of international law within the post-World War II international civilization, which has evolved into a post-colonial and post-Cold War world. This reorganisation may appear perplexing because it combines core aspects of classical international law with new types of amenability to law and new areas of intervention and regulation. International law demonstrates that the observed changes are both fascinating and disturbing, and they encourage us to keep a careful eye on them.

Frequently Asked Questions (FAQ’s)

1. Who is the father of international law?

Answer. Hugo Grotius(1583-1645), Dutch jurist and scholar.

2. Who does international law apply to?

Answer. States create public international law for the benefit of other states. It is founded on treaties that ratify mutual obligation and consent. If one state disregards a feature of international law, it jeopardises international law’s standing, as another state may do the same.

3. Where does international law come from?

Answer. The three basic sources and subsidiary sources of international law are listed in article 38 (1) of the Statute of the International Court of Justice (ICJ).


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