Grotius, who had now gained an international reputation, was given various high appointments, such as Public Historiographer, Attorney-General for the province of Holland, and councilor of Rotterdam. He went to England and was received by the King with the greatest cordiality, in spite of the recent dispute. He made many friends in England, notably with the celebrated scholar, Isaac Casaubon, who expressed the highest opinion of the great Dutchman in a letter written in April, 1613. He says:
I cannot say how happy I esteem myself in having seen so much of one so truly great as Grotius. A wonderful man! This I knew him to be before I had seen him; but the rare excellence of that divine genius no one can sufficiently feel who does not see his face and hear him speak. Probity is stamped on his features; his conversation savors of true piety and profound learning. It is not only upon me that he has made this impression; all the pious and learned to whom he has been introduced here have felt the same towards him; the King especially so.
Grotius returned to his country, where serious trouble awaited him. The cause of it all was, to begin with, a religious squabble between two sects, the one followers of Arminius, who believed in free-will, the other followers of Gomarus, who believed in predestination. This senseless dispute on a question which can never be settled—that is to say, whether man is free to shape his own destiny or whether his acts are all fated beforehand by God—was only an excuse for a quarrel between the more bigoted and intolerant religious sects who sided with Gomarus and the freer and more broadminded who followed Arminius. The whole country was convulsed by the controversy. The Arminians drew up a Remonstrance, which was answered by a Counter Remonstrance, and the Parliament issued an Edict of Pacification, urging tolerance and forbearance, which was largely due to the influence of Grotius.
Advantage was taken of this disturbance by Prince Maurice of Orange, the second son of William the Silent. He was an accomplished soldier, but a weak and untrustworthy statesman, and thought it a good opportunity to assert himself and satisfy his personal ambition to become a monarch. He undertook what he was pleased to call a pacific campaign, and seeing that the Gomarists were more popular than their opponents, many of whom favored a republic rather than a monarchy, he practically took their side.