Another of the more famous O'Neills of Tyrone was Owen Roe O'Neill (c. 1590–1649), a brilliant 17th-century military commander and one of the most famous of the O'Neill family of Ulster. He was the son of Art O'Neill, a younger brother of Hugh O'Neill, 2nd Earl of Tyrone. As a young man, he left Ireland in the Flight of the Earls to escape the English conquest of his native Ulster. He grew up in the Spanish Netherlands and spent 40 years serving in the Irish regiment of the Spanish Army, mainly in the Eighty Years' War against the Dutch Republic in Flanders, notably at the siege of Arras, where he commanded the Spanish garrison. O'Neill was, like many Gaelic Irish officers in the Spanish service, hostile to the English Protestant invasion of Ireland. He returned to Ireland during the Irish Rebellion of 1641 to command the Irish Ulster Army during the Irish Confederate Wars. He was reportedly poisoned by Cromwell's supporters and died in 1649.