Van Oldenbarnevelt studied law at Leuven, Bourges, Heidelberg and Padua, and traveled in France and Italy before settling in The Hague. He was a moderate Calvinist, so he supported William the Silent in his revolt against Spain, and fought in William's army.
During the two critical years which followed the withdrawal of Leicester, it was the statesmanship of the Advocate which kept the United Provinces from falling asunder through their own inherent separatist tendencies, and prevented them from becoming an easy conquest to the formidable army of Alexander of Parma. Fortunately for the Netherlands the attention of Philip was at their time of greatest weakness riveted upon his contemplated invasion of England, and a respite was afforded which enabled Oldenbarneveldt to supply the lack of any central organized government by gathering into his own hands the control of administrative affairs. His task was made the easier by the whole‐hearted support he received from Maurice of Nassau, who, after 1589, held the Stadholderate of five provinces, and was likewise Captain‐General and Admiral of the Union. The interests and ambitions of the two men did not clash, for Maurice's thoughts were centered on the training and leadership of armies and he had no special capacity as a statesman or inclination for politics. The first rift between them came in 1600, when Maurice was forced against his will by the States‐General, under the Advocate's influence, to undertake an expedition into Flanders, which was only saved from disaster by desperate efforts which ended in victory at Nieuwpoort. In 1598 Oldenbarneveldt took part in special embassies to Henry IV and Elizabeth, and again in 1605 in a special mission sent to congratulate James I on his accession.
The archdukes having consented to treat with the United Provinces as free provinces and states over which they had no pretensions, Oldenbarneveldt, who had with him the States of Holland and the majority of burgher regents throughout the county, was for peace, provided that liberty of trading was conceded.
Maurice and his cousin William Louis, stadholder of Frisia, with the military and naval leaders and the Calvinist clergy, were opposed to it, on the ground that the Spanish king was merely seeking an interval of repose in which to recuperate his strength for a renewed attack on the independence of the Netherlands.
For some three years the negotiations went on, but at last after endless parleying, on 9 April 1609, a truce for twelve years was concluded. All that the Dutch asked was directly or indirectly granted, and Maurice felt obliged to give a reluctant and somewhat sullen assent to the favorable conditions obtained by the firm and skillful diplomacy of the Advocate.
In 1610 the Arminians, henceforth known as Remonstrants, drew up a petition, known as the Remonstrance, in which they asked that their tenets (defined in the Five Articles of Remonstrance) should be submitted to a national synod, summoned by the civil government. It was no secret that this action of the Arminians was taken with the approval and connivance of the Advocate, who was what was styled a libertine, i.e. an upholder of the principle of toleration in religious opinions.
The Gomarists in reply drew up a Contra‐Remonstrance in seven articles, and appealed to a purely church synod. The whole land was henceforth divided into Remonstrants and Contra‐Remonstrants; the States of Holland under the influence of Oldenbarneveldt supported the former, and refused to sanction the summoning of a purely church synod (1613). They likewise (1614) forbade the preachers in the Province of Holland to treat of disputed subjects from their pulpits.
Obedience was difficult to enforce without military help; riots broke out in certain towns, and when Maurice was appealed to, as Captain‐General, he declined to act. He did more, though in no sense a theologian; he declared himself on the side of the Contra‐Remonstrants, and established a preacher of that persuasion in a church at the Hague (1617).
The States‐General, meanwhile, by a bare majority (4 provinces to 3) agreed to the summoning of a national church synod. The States of Holland, also by a narrow majority, refused their assent to this, and passed (August 4, 1617) a strong resolution (Scherpe Resolutie) by which all magistrates, officials and soldiers in the pay of the province were required to take an oath of obedience to the States of Holland on pain of dismissal, and were to be held accountable not to the ordinary tribunals, but to the States of Holland.
It was a declaration of sovereign independence on the part of Holland, and the States‐General of the Republic took up the challenge and determined on decisive action. A commission was appointed, with Maurice at its head, to compel the disbanding of the waardgelders. On the 31st of July 1618 the Stadholder appeared at Utrecht, which had thrown in its lot with Holland, at the head of a body of troops, and at his command the local levies at once laid down their arms.
His progress through the towns of Holland met with no opposition. The States party was crushed without a blow being struck.
Oldenbarneveldt was, with his friends, kept in strict confinement until November of that year, and then brought for examination before a commission appointed by the States-General. He appeared more than sixty times before the commissioners and was examined most severely upon the whole course of his official life, and was allowed neither to consult papers nor to put his defense in writing.
On 20 February 1619, Oldenbarneveldt was arraigned before a special court of twenty-four members, only half of whom were Hollanders, and nearly all his personal enemies. This hearing was in no sense a legal court, nor had it any jurisdiction over the prisoner, but the protest of the Advocate, who claimed his right to be tried by the sovereign province of Holland, whose servant he was, was disregarded.
It was in fact not a trial at all, and the packed bench of judges on Sunday, 12 May 1619, pronounced a sentence of death. On the following day the old statesman, at the age of seventy-one, was beheaded in the Binnenhof in The Hague. Such, to use his own words, was his reward for serving his country forty-three years. Oldenbarneveldt's last words to the executioner were purportedly as follows: "Make it short, make it short."
The Nederland Line ship Johan van Oldenbarnevelt carried his name from 1930 to 1963.