Whilst Grotius was thus employed in placing his son, Diederic entertained a design of entering into the Dutch service. His father was highly displeased with this project; and wrote to him, and to William Grotius, that it was most improper for him to expose his life for his cruellest enemies; and that Sweden was his true country, and to that kingdom he ought to devote his life, and from it to merit and expect honours. "If my son dislikes the activity of a military life, Grotius writes to his brother, he may find ease, and acquire honour in General Bannier's houshold, or by exercising his profession of Engineer. I shall always give him my assistance, and I hope I have as many friends elsewhere, as I have enemies in Holland. If my son disgraces himself so far, as to ask favours from the Dutch, he is unworthy to call me father. If he chuses rather to be an Ensign with you, than a Captain among others, he is mean-spirited, and forgetful of what he has been." Diederic had a design of writing the history of the Duke of Weymar; which project Grotius approved of, as worthy of a grateful mind. He sent him word, that if he would set about this work whilst he was with Marshal Bannier, he would make his court by it to that General, who had it in his power to reward him. Diederic at last complied with his father's desire, and went to Marshal Bannier's camp. He was made a prisoner of war by the Bavarians in an unfortunate action near Dillingue and Memingue, in the end of the year 1643. Grotius immediately set all his friends to work to procure his son's liberty: he wrote to the famous John de Vert, and applied to the Duke of Bavaria that he would be pleased to send him back as soon as possible: and at the same time wrote to his son to come to him as soon as he should be at liberty, that they might consult together what was best to be done. Diederic sent his father the history of the unfortunate action in which he was taken; and Grotius printed it to give copies to his friends, and to send others to the Swedish Ministry. Diederic was carried to Tubingen, from thence to Ulm, and confined in a citadel between Ulm and Augsburg: he did not continue there long: immediately on receiving his father's letter, the Duke of Bavaria gave orders that Diederic might be set at liberty, after settling his ransom, which was fixed at a thousand florins. He came to Paris, and on his arrival Grotius wrote a letter of thanks to the Elector of Bavaria, telling him, that as he had but one way to express his gratitude, namely by promoting a general peace, which his Electoral Highness wished for, he would do all in his power to bring it about. He wrote to Ketner the Bavarian Minister to the same effect.
Diederic went back to serve under Marshal Turenne in Germany, and made the campaign of 1644. He was again taken Prisoner, but soon released; and served in the end of the same campaign. He was detached by the Duke d'Anguien and Marshal Turenne to take Fridelshem and Neudstad, and was afterwards sent by them to the Landgravine of Hesse: he acquitted himself with honour of all the commissions that were given him. The Duke d'Anguien spoke of him in the highest terms; and the Landgravine received him in the best manner, in consideration of the services which his father had done to the house of Hesse: he was sent a second time by Marshal Turenne to the Landgravine. The Duke d'Anguien promised to take care of this youth's fortune; and the approbation of a prince, who was the Mars of his time and knew men so well, is the highest elogium that could be given of Diederic.
He came to an unhappy end when but young and unmarried. Queen Christina having abdicated the Crown in favour of Charles Gustavus, Diederic and Cornelius Grotius took a resolution to wait on that Prince, who had known and highly esteemed their father in France, with an intention to offer him their services, and get employment. Setting out from Holland with this design, they were got between Embden and Bremen, halfway to Hamburg, when a villain, who had served Diederic several years as his valet, resolved to murder both the brothers for the sake of their money: he went in the night-time into Diederic's chamber, and shot his master dead while asleep: he was preparing to serve Cornelius Grotius in the same manner, but he was awake: he happened to be employed in composing a Latin epigram. On hearing the shot, he took a pistol which lay on a chair by his bed side, and seeing the murderer advance softly to him (it was moon-light) he fired, and laid him flat on the floor: the people of the inn got up on the noise, and delivered the villain, who was dangerously wounded, into the hands of justice, and he was broke on the wheel.
Hugo Grotius had also three daughters, Frances, Mary, and Cornelia; Frances, the youngest, was born in October, 1626, before her time, her mother being delivered of her in the eighth month: accordingly this young person was short-lived, for she died in the beginning of the year 1628. Mary, his second daughter, died at Paris in the month of March, 1635, of the fatigue and cold she received in her journey to that city. Grotius informed his father of her death by a letter[772] dated March 23, 1635, in which he tells him she died almost without pain, and with a deep sense of religion. "My wife and I, says he, bear this misfortune like people accustomed to adversity: besides, why should we call her death a misfortune? has not God a right to take back what he gave? and ought not we to flatter ourselves that she is arrived at that happy state, which the young ought to long after as much as the old? We are delivered from the care of procuring a husband for her: perhaps we should have had much difficulty to find one that would have been agreeable to her and to all her family: and even if we should have found one that pleased us all at first, would there not have been room to apprehend that he had concealed his true character for a time, and that he would afterwards make her unhappy? She is now delivered from the pains of bearing children, and bringing them up. More happy than her mother, she will not see judges incensed against her husband, because he is innocent: she will not be obliged to shut herself up in prison for her husband; nor to lead a wandering life to accompany him. Let us congratulate her that God has taken her out of the world before she knew too much of the evil or what are called the good things of it. Let us congratulate ourselves on her having lived with us as long as life was agreeable to her, and free from any mixture of bitterness. What is there at present in Christendom to make us desire life? Divisions in the Church, bloody wars, men slaughtered, women violated, cruel murders, and multitudes reduced to beggary; Bohemia, Moravia, and Silesia pillaged; the heirs of the most noble families reduced to the necessity of living on alms, if it can be called living to drag out their days in misery, wishing for death, which alone can put an end to it."
Cornelia, the eldest of Grotius's daughters, who survived her father, married John Barthon, Viscount of Mombas, a Gentleman of Poitou, who was obliged to quit France for having displeased Lewis XIV. He went to Holland, from whence he was also forced to fly, having been involved in the misfortunes wherein the De Wits perished, and which gave Peter Grotius, his brother-in-law, so much uneasiness.
Grotius had a brother named William, with whom he kept up the greatest intimacy during his whole life, and made him the confident of his studies and designs. It appears by his letters that they lived in the strictest friendship. Hugo, who was the eldest, contributed to his brother's education, and directed his studies. We have a letter from Grotius to his brother, dated at Rotterdam September 28, 1614, containing a plan of study. "I am of opinion, says he, that in order to acquire the knowledge of Law, before you touch upon law tracts you should read with attention Aristotle's second and fifth book of Ethics, to Nicomachus, or the excellent paraphrase of them published by Heinsius; then Aristotle's Rhetoric, with the learned commentary on it; afterwards Cicero's Offices, the Paradoxes, De Finibus, Of Laws, the Topica, and De Inventiene. I could wish that whilst reading you would make extracts, or at least mark in the margin of your book whatever has relation to the Law of Nature and of Nations, to the origin of Laws and Magistrates, to Jus publicum et privatum. When you have done this, we shall think of the rest." It was Grotius who corrected his brother's Law Theses.
William Grotius came to France in 1617 to learn the language; and retiring to Senlis made great progress in it: he purposed to go to Tours, and Grotius approved of his journey, because the air was pure, and they spoke good French there.
William Grotius, as well as his brother, had a turn for theological studies: he wrote something in verse on the Decalogue, which Grotius mentions in a letter dated from his prison at Louvestein, November 1, 1620. "I have read with pleasure, he says, what you have done on the Decalogue: the maxims are excellent, and the verses easy."
William had his brother's confidence during his whole life. Grotius writes to him from Paris, April 14, 1622, "You are never weary of assisting me under my afflictions: if ever fortune enables me to testify my gratitude, I will forgive her all the tricks she has played me." He was desirous, in the end of the year 1622, that his brother should settle his matters so, as to come to see him in the beginning of the following year; but this journey did not take place. Grotius's disgrace affected his brother: he despaired of attaining to honours, and Grotius advised him to think only of raising himself by the study of the Law.
In April 1623 he married Alida Grasvinkel. About this time a Dutchman was seized at Lillo, with letters from William Grotius to his brother. It was expected that something would be found in them against the State, and they talked of nothing less than imprisoning him; but notwithstanding the malice of his enemies, they could not find the least pretext from these letters to trouble him. In the mean time William followed the profession of an Advocate with much success: Grotius compliments him on it in a letter of the 28th of November, 1625, in which he tells him, that the life he led in shining at the bar was much more agreeable than that which is spent in public employments.