James Ussher (1581-1656) was a scholar, a politician and a Church of Ireland bishop. He was born in Dublin and graduated from Trinity College, Dublin. He became a professor of theology at Trinity College until 1617. He was ordained in 1601.
He was strongly anti-Catholic, one of of his works was An answer to a challenge made by a Jesuit in Ireland (1624). In his A discourse of the religion anciently professed by the Irish and British (1631) he made that the Church of Ireland was the rightful heir of St Patrick.
He opposed the imposition of the 39 Articles upon the Church of Ireland and argued that the terms Puritan and Reformed were synonymous.
From 1625-1656 he was the Archbishop of Armagh and Primate of All Ireland. His work on chronology concluded that the earth was created in 4004 BC.
Oliver Cromwell ensured that Ussher's funeral was paid for by the state and held in Westminster Abbey.
Several of Ussher's works are available here: http://www.prdl.org/author_view.php?a_id=55