King Richard III was defeated at the Battle of Bosworth Field in 1485. This decisive encounter marked the end of the Wars of the Roses, a series of civil wars for control of the English throne between the houses of Lancaster and York. In the aftermath, Henry Tudor, who became Henry VII, ascended to the throne, establishing the Tudor dynasty. Richard III's defeat symbolized the decline of the Plantagenet rule and was pivotal in shifting the balance of power, ultimately leading to significant reforms and changes in the British monarchy.