Meanwhile strong and influential efforts were made for leniency.  The French ambassador, Aubrey du Maurier, during the trial did his utmost to secure fair treatment for the Advocate; and a special envoy, Chatillon, was sent from Paris to express the French king’s firm belief in the aged statesman’s integrity and patriotism based on an intimate knowledge of all the diplomatic proceedings during and after the negotiations for the Truce.  But these representations had no effect and were indeed resented.  Equally unfruitful were the efforts made by Louise de Coligny to soften the severity of her step-son’s attitude.  Even William Lewis wrote to Maurice not to proceed too harshly in the matter.  All was in vain.  The Prince’s heart was steeled.  He kept asking whether the Advocate or his family had sued for pardon.  But Oldenbarneveldt was far too proud to take any step which implied an admission of guilt; and all the members of his family were as firmly resolved as he was not to supplicate for grace.  Few, however, believed that capital punishment would be carried out.  On Sunday, May 12, however, sentence of death was solemnly pronounced; and on the following morning the head of the great statesman and patriot was stricken off on a scaffold erected in the Binnenhof immediately in front of the windows of Maurice’s residence.  The Advocate’s last words were a protestation of his absolute innocence of the charge of being a traitor to his country; and posterity has endorsed the declaration.

That Oldenbarneveldt had in the last two years of his life acted indiscreetly and arrogantly there can be no question.  His long tenure of power had made him impatient of contradiction; and, having once committed himself to a certain course of action, he determined to carry it through in the teeth of opposition, regardless of consequences and with a narrow obstinacy of temper that aroused bitter resentment.  His whole correspondence and private papers were however seized and carefully scrutinised by his personal enemies; and, had they found any evidence to substantiate the charges brought against him, it would have been published to the world.  It is clear that not a shred of such evidence was discovered, and that the Advocate was perfectly innocent of the treasonable conduct for which a packed court condemned him to suffer death.  Such was the reward that Oldenbarneveldt received for life-long services of priceless value to his country.  He more than any other man was the real founder of the Dutch Republic; and it will remain an ineffaceable stain on Maurice’s memory that he was consenting unto this cruel and unjust sentence.

Sentences of imprisonment for life were passed upon De Groot and Hoogerbeets.  They were confined in the castle of Loevestein.  The conditions of captivity were so far relaxed that the famous jurist was allowed to receive books for the continuance of his studies.  Through the ingenuity and daring of his wife De Groot contrived to escape in 1621 by concealing himself in a trunk supposed to be filled with heavy tomes.  The trunk was conveyed by water to Rotterdam, from whence the prisoner managed to make his way safely to France.