 Such was the hatred he henceforth conceived against his former benefactor, that he did his very utmost to effect Oldebarneveldt's ruin.However, he was not a member of the court that convicted Oldenbarnevelt in the Trial of Oldenbarnevelt, Grotius and Hogerbeets as Chisholm mistakenly reports.He afterwards became the confidential counselor of Maurice, Prince of Orange, and afterwards of Frederick Henry, Prince of Orange, in their conduct of the foreign affairs of the republic.