The Hague played an important part in Grotius’ life: it was where his career began, where he and Maria started their family and where eventually his trial would be held. By 1599 The Hague was already the most important city of the Dutch Republic in terms of political power: it hosted the legislative, executive, and judiciary bodies of the wealthy and powerful province of Holland, as well as the States-General, the legislative body deciding on federal affairs. It was also the seat of Maurice of Orange, the son of the country’s founding father William of Orange. As the Stadtholder, Maurice was officially a civil servant and the military commander in chief, but his considerable political power was kept in check by other important political figures, most notably Oldenbarnevelt. When Grotius first moved to The Hague, he took lodgings with Johannes Uytenbogaert, a minister at Maurice’s Calvinist court, who was to become a lifelong friend and a major figure in events to come. J.J. van Harn, C. Bos, Caerte van 's Gravenhage, map, 1616 [COLLBN Port 16 N 51]

Mare Liberum (known nowadays in English as The Free Sea) was published in 1609 in the form of a pamphlet. It only later on became clear that it was originally a chapter of a much larger manuscript: De Iure Praedae (On the Law of Prize and Bounty), the only surviving copy of which can be found in Leiden University’s Special Collections. The drafting and printing history behind the pamphlet and how it relates to the VOC is too complex to explain in a few words here. What is worth emphasizing however is that the concept of freedom of seas, the idea that the sea is a common heritage of mankind, free for all nations to use for trade and travel, as argued by Grotius in this pamphlet, is still one of the foundational principles of the international law of the sea nowadays. Hugo de Groot, Mare liberum, book, 1609 [20643 F 18]

At the start of the century, an argument had developed between two Leiden University theologians, Franciscus Gomarus and Jacobus Arminius, both portrayed here by engraver Willem van Swanenburgh. The argument concerned a number of crucial points relating to Calvinist doctrine, most notably the belief that God has predestined some to be saved and others to eternal damnation, regardless of the individual’s actions. Arminius argued against this crucial tenet of Calvinism, claiming that human beings have free will and can make decisions that will lead to salvation. During the Twelve Years’ Truce (1609-1621), the conflict escalated, pitting the Remonstrants, a relatively small group of Arminius’ followers led by Grotius’ close friend Uytenbogaert, against the orthodoxy – and power - of the Dutch Reformed Church. Oldenbarnevelt was sympathetic towards the Remonstrants: he argued for toleration and offered them protection. Willem van Swanenburg, Portraits of Gomarus and Arminius, prints [BN 542 and BN 47]

Grotius’ correspondence from this period clearly shows that his own religious views were veering towards Arminianism and that he supported Oldenbarnevelt and his vision of religious tolerance and co-existence. However, he initially remained reluctant to express these ideas too openly or explicitly. In this letter, he writes Oldenbarnevelt that the subject of the Remonstrants and the English response to the conflict will come up during his diplomatic mission to England in the spring of 1613. King James I, Grotius writes, will want to discuss the issue with him but he is in no hurry (‘nyet te dringhen nochte my te verhaesten’) to do so. Hugo de Groot to Johan van Oldenbarnevelt, letter, 1613 [PAP 2]

As Scaliger had predicted, Grotius would eventually become the Pensionary of a Dutch town. In 1613, he took the next step in his already impressive career and became Pensionary of Rotterdam, at this stage the seventh city of the Republic. This portrait of Grotius was made by Claes Jansz. Visscher and shows him in his role of ‘Pencionaris der Stat Rotterdam’, the highest official that served the city, mainly in an advisory role on judicial and political matters. Although Grotius was delighted with his important and lucrative new position, he did remain attached to The Hague, to the extent that he had a clause added to his contract that he was allowed to stay and work in The Hague from time to time until a new advocate-fiscal had been appointed. C.J. Visscher, Portrait of Johan van Oldenbarnevelt as pensionary, print, c.1613 .

Perhaps encouraged by his new position as the Pensionary of Rotterdam, a Remonstrant stronghold, Grotius stopped being cautious about his support for the Arminian cause in the summer of 1613. In August that year, he wrote a reply to a pamphlet written by Sibrandus Lubbertus, an orthodox Calvinist theologian at the University of Franeker, in which he had criticized the succession of Arminius at Leiden University. Ordinum Pietas, published in Latin, Dutch (in a translation by Uytenbogaert) and French in October 1613. The first part of the book addresses the succession issue but the second and third parts explicitly defend Arminian principles as well as the government’s autonomy against the Calvinist church. Ordinum Pietas is a furious and unapologetic book, and marks a point of no return. Grotius was now firmly in the Remonstrant camp, and despite a flood of counter-attacks from the Counter-Remonstrants, he would continue to openly advocate religious toleration and reject the interference of the Dutch Reformed Church in state matters. Hugo de Groot, Ordinum pietas, book, 1613 [1498 C 19]

Over the next years, the tension between the Remonstrants and Counter-Remonstrants became increasingly strong and political, especially after Stadtholder Maurice began openly supporting the latter. In August 1618, Maurice committed a coup d’état and had Oldenbarnevelt, Grotius and a number of others associated with the Arminian cause arrested. Grotius was imprisoned on 29 August 1618 and was not allowed to see anyone while on remand, not even his wife Maria. On 19 October, she wrote him this letter, to keep her husband informed of the events outside the prison and to tell him not to worry about her. She also tells Grotius that she has heard rumours that he has tried to win back Maurice’s favour but she does not believe this. Maria van Reigersberch to Grotius, letter, 1618 [PAP 2]