Mary I was proclaimed Queen of England, deposing Lady Jane Grey after nine days of de facto rule.

Mary I, also known as Mary Tudor, was Queen of England and Ireland from July 1553 and Queen of Spain as the wife of King Philip II from January 1556 until her death in 1558. She made vigorous attempts to reverse the English Reformation, which had begun during the reign of her father, King Henry VIII. Her attempt to restore to the Church the property confiscated in the previous two reigns was largely thwarted by Parliament but, during her five-year reign, more than 280 religious dissenters were burned at the stake in what became known as the Marian persecutions, leading later commentators to label her "Bloody Mary".

This list of kings and reigning queens of the Kingdom of England begins with Alfred the Great, who initially ruled Wessex, one of the seven Anglo-Saxon kingdoms which later made up modern England. Alfred styled himself king of the Anglo-Saxons from about 886, and while he was not the first king to claim to rule all of the English, his rule represents the start of the first unbroken line of kings to rule the whole of England, the House of Wessex.

Lady Jane Grey, also known as Lady Jane Dudley after her marriage, and nicknamed as the "Nine Days Queen", was an English noblewoman who was proclaimed Queen of England and Ireland on 10 July 1553 and reigned until she was deposed by the Privy Council of England, which proclaimed her cousin, Mary I, as the new Queen on 19 July 1553. Jane was later beheaded for high treason.