Johan van Oldenbarnevelt (Dutch pronunciation: [ˈjoːɦɑn vɑn ɔldə(n)bɑrnəvɛlt]),Lord of Berkel en Rodenrijs (1600), Gunterstein (1611) and Bakkum (1613) (14 September 1547 – 13 May 1619) was a Dutch statesman who played an important role in the Dutch struggle for independence from Spain.
Van Oldenbarnevelt was born in Amersfoort. He studied law at Leuven, Bourges, Heidelberg and Padua, and traveled in France and Italy before settling in The Hague. He supported William the Silent in his revolt against Spain, and fought in William's army. In his later years he was a supporter of the Arminians, in the religious-political controversy which split the young Dutch Republic.
Van Oldenbarnevelt served as a volunteer for the relief of Haarlem (1573) and again at Leiden (1574). He was married in 1575 to Maria van Utrecht. In 1576 he obtained the important post of pensionary of Rotterdam, an office which carried with it official membership of the States of Holland. In this capacity his industry, singular grasp of affairs, and persuasive powers of speech speedily gained for him a position of influence. He was active in promoting the Union of Utrecht (1579) and the offer of the countship of Holland and Zeeland to William the Silent (prevented by Williams death in 1584). He was a fierce opponent of the policies of the Earl of Leicester, the governor‐general at the time, and instead favoured Maurice of Nassau, a son of William. Leicester left in 1587, leaving the military power in the Netherlands to Maurice. During the governorship of Leicester, Van Oldenbarnevelt was the leader of the strenuous opposition offered by the States of Holland to the centralizing policy of the governor.