Mary was the only child of Henry VIII by his first wife, Catherine of Aragon, to survive to adulthood. Her younger half-brother Edward VI (son of Henry and Jane Seymour) succeeded their father in 1547 at the age of nine. When Edward became mortally ill in 1553, he attempted to remove Mary from the line of succession because he supposed, correctly, that she would reverse the Protestant reforms that had begun during his reign. On his death, leading politicians proclaimed Lady Jane Grey as queen. Mary speedily assembled a force in East Anglia and deposed Jane, who was ultimately beheaded. Mary was—excluding the disputed reigns of Jane and the Empress Matilda—the first queen regnant of England. In 1554, Mary married Philip of Spain, becoming queen consort of Habsburg Spain on his accession in 1556.