The Tudor dynasty or House of Tudor was a prominent European royal house of Welsh origin that ruled the Kingdom of England and its realms, including the Lordship and Kingdom of Ireland, from 1485 until 1603. Its first monarch was Henry Tudor, a descendant through his father, although ultimately not male line, of the rulers of the Welsh Kingdom of Deheubarth. Through his mother he descended from a legitimized 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, extirpated. 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 tried to make substance of it.
In total, five Tudor monarchs ruled their domains for just over a century (Lady Jane Grey, the granddaughter of Henry VIII's younger sister Mary, was declared Queen for a period of nine days in 1553, but is usually regarded as a usurper rather than a monarch). Henry VIII of England was the only male-line male heir of Henry VII to live to the age of majority; and issues around the Royal succession (including marriage, divorce, and the succession rights of women) became major political themes during the Tudor era.
The Tudor line failed in 1603 with the death of Elizabeth I of England, who died without issue. Through secret negotiations with her cousin James, King of Scotland, (whose great-grandmother was Henry VIII's elder sister, Margaret) Elizabeth arranged the succession of the House of Stuart to the English throne, uniting the Kingdoms of England and Scotland in a personal union.
The Tudors descended on the mother's side from John Beaufort, one of the illegitimate children of the 14th century English Prince John of Gaunt, 1st Duke of Lancaster (the third surviving son of Edward III of England) by Gaunt's long-term mistress Katherine Swynford. The descendants of an illegitimate child of English Royalty would normally have no claim on the throne, but the situation was complicated when Gaunt and Swynford eventually married in 1396 (25 years after John Beaufort's birth). In view of the marriage, the church retroactively declared the Beauforts legitimate by way of a papal bull the same year, confirmed by an Act of Parliament in 1397. A subsequent proclamation by John of Gaunt's legitimate son, King Henry IV, also recognized the Beauforts' legitimacy, but declared them ineligible to ever inherit the throne. Nevertherless, the Beauforts remained closely allied with Gaunt's legitimate descendants from his first marriage, the Royal House of Lancaster.
John Beaufort's granddaughter Lady Margaret Beaufort, a considerable heiress, was married to Edmund Tudor, 1st Earl of Richmond. Tudor was the son of Welsh courtier Owain Tewdr (anglicised to Owen Tudor) and Katherine of Valois, widowed Queen Consort of the Lancastrian King Henry V. Edmund Tudor and his siblings were either illegitimate, or the product of a secret marriage, and owed their fortunes to the good will of their legitimate half-brother King Henry VI. When the House of Lancaster fell from power, the Tudors followed.
Edmund's son Henry Tudor, born in Pembroke, grew up in south Wales and in exile in Brittany, while his mother Lady Margaret remained in England and remarried, quietly advancing the cause of her son in a Kingdom now ruled by the rival House of York. With most of the House of Lancaster now dead, Henry proclaimed himself the Lancastrian heir. Capitalizing on the unpopularity of King Richard III, his mother was able to forge an alliance with discontented Yorkists in support of her son, who landed in England and defeated Richard III at the Battle of Bosworth Field in 1485, proclaiming himself King Henry VII. By marrying Richard III's niece, Elizabeth of York, Henry VII successfully bolstered his own disputed claim to the throne, whilst moving to end the Wars of the Roses by presenting England with a new dynasty, of both Lancastrian and Yorkist descent. The new dynasty was symbolized by the "Tudor Rose", a fusion of the White Rose symbol of the House of York, and the Red Rose of the House of Lancaster.