The Tudor dynasty or House of Tudor was a European royal house of Welsh origin that ruled the Kingdom of England and its realms, including the Lordship of Ireland, later the Kingdom of Ireland, from 1485 until 1603. Its first monarch was Henry VII, a descendant through his mother of a legitimised branch of the English royal House of Lancaster. The Tudor family rose to power in the wake of the Wars of the Roses, which left the House of Lancaster, to which the Tudors were aligned, extinct.

Henry Tudor was able to establish himself as a candidate not only of the traditional Lancastrian supporters, but of discontented supporters of the rival House of York, and rose to capture the throne in battle, becoming Henry VII. His victory was reinforced by his marriage to Elizabeth of York, symbolically uniting the former warring factions under a new dynasty. The Tudors extended their power beyond modern England, achieving the full union of England and the Principality of Wales in 1542, (Laws in Wales Acts 1535–1542); and successfully asserting English authority over the Kingdom of Ireland. They also maintained the traditional (i.e. nominal) claims to the Kingdom of France, but none of them tried to make substance of it, though Henry VIII fought wars with France to try to reclaim that title. After him, his daughter Mary I lost the claim on France forever with the Fall of Calais.