Mary I was the Queen of England and Ireland from July 1553 until her death. Her executions of Protestants led to the posthumous sobriquet "Bloody Mary".
She was the only child of Henry VIII and 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.
When Edward became mortally ill in 1553, he attempted to remove Mary from the line of succession because of religious differences. On his death their first cousin once removed, Lady Jane Grey, was proclaimed queen. Mary 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. Philip in his turn became her co-ruler in England.
Mary is remembered for her restoration of Roman Catholicism after her half-brother's short-lived Protestant reign. During her five-year reign, she had over 280 religious dissenters burned at the stake in the Marian persecutions. After her death in 1558, her re-establishment of Roman Catholicism was reversed by her younger half-sister and successor Elizabeth I, daughter of Henry and Anne Boleyn.
The Royal style of Queen Mary I was "By the Grace of God, Queen of England, France and Ireland, Defender of the Faith, and of the Church of England and of Ireland in Earth Supreme Head".