Hugo de Groot (Grotius)

Father of international law

by Chloë Fonk1

The legitimacy of the Dutch Revolt (1568-1588, read our article on this subject) against Filips II was partially justified by natural law arguments. The Dutch Republic kept defending her position with natural law arguments, even in the following period.

With natural rights we mean universal rules that are always applicable, anywhere in the world. This is not to be mistaken with norms that are tied to a certain culture or a certain period.

Perhaps this is why it is not surprising that one of the most important representatives of the idea of natural rights was a Dutchman, Hugo Grotius.

Hugo Grotius at the age of 15, drawing of Jacob de Gheyn 1599. Picture of the Amsterdam Historical Museum2

Hugo Grotius (also called ‘Huig de Groot’, ‘Hugo Grocio’ or ‘Hugo de Groot’) was born in Delft in 1583. His family belonged to the prominent citizens. Hugo was gifted and mastered Greek and Latin at a young age. At the age of eleven, he went to study at Leiden University. His giftedness was also noted abroad.  In 1598, when he was fifteen, he participated in a Dutch delegation that visited the French court. King Henry IV of France received Hugo with the words: ‘‘Behold, the miracle of Holland’’. The same year, Hugo graduated in Orléans (France) and obtained his doctorate in law.

In 1599, Hugo settled in The Hague as an attorney at the Court of Holland. This was the highest court in the province of Holland. He was appointed judge-advocate (prosecutor) at this Court.

He used his great knowledge of the law of Holland to write a standard on this subject, called ‘Inleydinghe tot de Hollandsche Rechtsgeleerdheydt’ (1631) (translated from Middle Dutch: ‘Introduction to Dutch Law’). Noteworthy is that he wrote this work in Dutch. He normally wrote his books in Latin, the international language of science. However, with this work he wanted to prove that Dutch was also suitable for science.

Hugo Grotius did not only occupy himself with law. Like many scholars of that period, he was engaged in other studies too. In 1610, his history of Holland ‘De antiquitate Reipublicae Batavicae (Tractaet vande oudheyt vande Batavische nu Hollandsche Republique)’ was published (translation: ‘The Antiquity of the Batavian, now Dutch Republic’). In this work he defended the conception that the Regional States have always possessed sovereignty in the Low Countries. Counts were mere officials who were appointed by the States to protect them against the claims of European kings.

These ideas were not tenable, but they did well with the regents. The regents were powerful merchants who called the shots in the cities. Every city had its own representatives in the Regional States. The States of Holland consisted almost entirely of these representatives of cities.

In 1613, Hugo Grotius became a member of the States of Holland, as a representative of the city of Rotterdam. He would soon become the right of the Dutch Land's Advocate of Holland, Oldenbarnevelt. The Land's Advocate had to execute the decisions of the States of Holland. Holland was the wealthiest and most powerful region of the Dutch Republic. Inevitably, this made Oldenbarnevelt one of the two most powerful people within the Republic.

The stadtholder, Maurits, was the other powerful person. He was the commander of the armed forces and he was also entitled to appoint regents for many important functions. The stadtholders were the descendants of the great Revolt leader William the Silent (Dutch: Willem van Oranje).

Things did not go well between the Land's Advocate and the stadtholder. Eventually, this would lead to a fierce power struggle between the two. Hugo Grotius also wrote tragedies and the conflict that would follow would make him one of the leading roles in his own tragedy.

Peace talks were held with Spain in 1607. Spain, along with Portugal, demanded the exclusive right of trade with India (the areas east of Cape of Good Hope). The Spaniards based this on the treaties of Tordesillas (1494) and of Zaragoza (1529). Under the mediation of the pope, divisions of Asia and America were made between Spain and Portugal.

However, the Dutch East India Company (Dutch: VOC) was established in the Republic. The VOC also traded with the Asian regions. The demand of the Spaniards meant that the VOC would have to cease her activities.

Therefore, the VOC asked Hugo Grotius to defend her rights to navigate in India. Hugo Grotius used a chapter from his earlier book on the law of capture (De iure praedae commentarius). This chapter developed into a separate book, Mare Liberum.

The plea of Hugo has the natural law as principle. The natural law is, according to Hugo, the general human idea that regulates society. It would therefore also apply to the coexistence of people and thus on the use of the sea.

The essence of this book is that the sea belongs to everyone. Every nation has the right to sail on all seas and to trade with anyone. He wrote: ‘‘The purpose of this essay is to show that the Dutch, the residents of the Republic of the United Netherlands, have the right to navigate to Asia and to trade with the inhabitants. It is a basic right of all states to go to another country and to trade with them.  Countries that undermine this right, affect the natural law. The oceans are all created by God and may therefore be freely navigated by everyone. The winds blow in all directions and they bring ships from all regions to their location.’’

One of the arguments he argued to defend his thesis was that possession could only be obtained through labor. The sea cannot be edited and can therefore be no one’s possession (res nullius). Everyone may use it.

In his book, Hugo uses the term ‘international law’ for the first time.

The peace talks with Spain resulted in a Twelve Years' Truce (1609-1621). Oldenbarnevelt and many of the regents in the province of Holland were in favor of this truce, but they had rather made peace. Peace is advantageous for trading and thus advantageous for the interest of the regents, who were also merchants.

The stadtholder did not have interest in this truce. His influence as commander of the armed forces in times of peace would decrease. The stadtholder had a lot of support from people in the non-Dutch regions. Even the populace in Holland often supported the stadtholder because of dissatisfaction with the power of the merchants.

A discussion about the predestination theory erupted within the Calvinist Reformed Church. Theologian Arminius argued that there was indeed a free will and that man could make ​​his own decisions. God only knew in advance what choices a person would make in his life. However, his opponent Gomarus stuck to the doctrine of Calvin. God determined the entire life of man and therefore who would be chosen to join him in heaven (predestination theory).

The followers of Arminius, called Remonstrants, wanted a tolerant Protestant church. Multiple other conceptions ought to be allowed within the tolerant Protestant church. The supporters of Gomarus, called Counter-Remonstrants, were fiercely against.

Hugo Grotius belonged to the Remonstrants. He continuously pleaded for tolerance and against dogmatism in his works. He was a typical representative of the Dutch regents, who wanted the power to be carried out by the States of Holland as much as possible. Being the right of Oldenbarnevelt, the country lawyer, he would continuously defend the interests of the regents and of the Remonstrants during the Twelve Years' Truce.

In castle of Loevestein
Hugo Grotius was put in prison from 1619

The tensions reached a peak in 1518. Supported by the armed forces and a large part of the remaining regions, Maurits seized power. He incarcerated Oldenbarnevelt and his most important faithful ones. Oldenbarnevelt was executed after a mock trial. Hugo Grotius got life imprisonment and was transferred to Loevestein Castle.

He knew a spectacular way to escape in 1621. He was allowed to read books in prison. These books were brought to him in a heavy chest. With the help of his wife and maid, who were allowed to stay with him in prison, he hid himself inside the chest when they came to pick it up. He fled to France, where he was cordially received by King Louis XIII.

He wrote De jure belli ac pacis (English: On the Law of War and Peace) in exile. This book would make him the founder of international law.


In a book chest Hugo Grotius managed to
escape the castle in 1621.

The natural law is obviously used as a guideline. In the introduction he wrote: ‘‘to prove the (natural) law, I also used the sayings of philosophers, historians, poets, even orators, not because they are unconditionally trustworthy because the parties only wish to prove their case with evidence; it is because, when many people from different periods and places stick to the same, this indicates a universally valid ground.

Because Hugo Grotius applies the natural law to states, it must also be applied to wars between those states. This generates the laws of war.

Two types of wars exist according to Hugo: the righteous and the unrighteous.

Righteous wars are wars that are carried out to defend, wars to get back what was taken away and wars for punishment of crimes. This definition also means that one of the warring parties always enters an unrighteous war.

The best is when wars are prevented by means of conferences and arbitration. These ideas of Hugo would have an enormous influence on later thinkers and they would eventually be realized.

A peace conference was held in The Hague in 1899 on the initiative of the Russian Tsar Nicholas II. Nicholas II supported the idea to prevent war by means of arbitration. The establishment of a Court of Arbitration was decided upon during the conference. The Permanent Court of Arbitration has been housed in the Peace Palace in The Hague since 1913. The Peace Palace is also home to the International Court of Justice, part of the United Nations.

The American professor Woodrow Wilson (1856-1924) was an admirer of Hugo Grotius and he devoted his classes to his ideas. He became president of the United States of America in 1913. In 1917, he was responsible for the fact that his country participated in the First World War. At the end of this war, during the peace conference of Paris, he would defend the ideas of Hugo Grotius to realize these. This leaded to the establishment of the League of Nations, the predecessor of the United Nations.

Hugo tried to get back to his fatherland during his life. Much to his grief, he remained a persona non grata.

His motto was ruit hora (time flies). He was an ambassador of Sweden in France eventually. During his return journey from a visit to Sweden, his ship was caught by a storm in the Baltic Sea. Hugo survived, but died on 28 August 1645 in Rostock of exhaustion due to the wreckage. His time was gone. Yet, his ideas are far from gone. His legacye, international law, is of inestimable significance. The Hague, once his city, with several international courts is still a center of that right.



  1. In collaboration with Henk Rijkeboer.

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