The "Act of Succession" refers to a series of laws enacted in England during the 16th century, primarily under the reign of Henry VIII. These laws determined the line of succession to the English throne, particularly regarding the legitimacy of Henry VIII's children. The first Act of Succession in 1534 declared that Henry's marriage to Catherine of Aragon was invalid and recognized his marriage to Anne Boleyn and their offspring as legitimate heirs. Subsequent Acts of Succession further clarified the rules of succession, including the exclusion of Mary and Elizabeth, the daughters of Catherine and Anne, respectively, from the throne. The laws played a crucial role in the establishment of the Tudor dynasty and shaped the future of the English monarchy.