History of England
With Henry VII's accession to the throne in 1485, the Wars of the Roses came to an end, and Tudors would continue to rule England for 118 years. Traditionally, the Battle of Bosworth Field is considered to mark the end of the Middle Ages in England, although Henry did not introduce any new concept of monarchy, and for most of his reign his hold on power was tenuous. He claimed the throne by conquest and God's judgement in battle. Parliament quickly recognized him as king, but the Yorkists were far from defeated. Nonetheless, he married Edward IV's eldest daughter Elizabeth in January 1486, thereby uniting the houses of York and Lancaster.
List of English monarchs
The Tudors descended in the female line from John Beaufort, one of the illegitimate children of John of Gaunt (third surviving son of Edward III), by Gaunt's long-term mistress Katherine Swynford. Those descended from English monarchs only through an illegitimate child 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 via a papal bull the same year, and Parliament did the same in an Act in 1397. A subsequent proclamation by John of Gaunt's legitimate son, King Henry IV, also recognised the Beauforts' legitimacy, but declared them ineligible ever to inherit the throne. Nevertheless, the Beauforts remained closely allied with Gaunt's other descendants, the Royal House of Lancaster.