Lady Jane Grey (ca. September-October, 1537 – February 12, 1554), a great-grand-daughter of Henry VII of England, reigned as uncrowned queen regnant of the Kingdom of England for nine days in 1553.
Jane's mother, Lady Frances Brandon, had a claim to the throne as the daughter of King Henry VIII's younger sister Mary Tudor. (Frances Brandon's father, Charles Brandon, Duke of Suffolk, had
married Mary Tudor as her second husband.) Jane's status as a monarch remains controversial, as her succession contravened an Act of Parliament. The Act of Succession of 1543 enabled the will of King Henry VIII to specify the order of succession of his children. In contrast, the later published will of King Edward VI of June 1553 naming Lady Jane Grey as his heir presumptive may have contravened customary testatory law because Edward, then just 15 years old, had not legally reached the legal testatory age of 21. But more importantly, many legal theorists of the day believed that the monarch could not contravene an Act of Parliament, even in matters of the succession, but must instead seek a new Act specifically granting such powers.
Though Jane's "accession" may have breached the laws of England, many powers of the land proved willing to accept her as Queen of England, even if only as part of a power-struggle to stop Henry's elder daughter, Princess Mary (a Roman Catholic) from acceding to the throne. Jane's brief rule ended, however, when the authorities revoked her proclamation as queen. The subsequent Marian régime eventually had her executed for treason.
Popular history sometimes refers to Lady Jane as "The Nine Days' Queen" (July 10 - July 19, 1553) or as "The Thirteen Days' Queen" (July 6 - July 19, 1553) — owing to uncertainties as to when she actually succeeded to the throne and as to when her formal deposition took place. Most commonly the tag occurs as "Nine Days". Historians have taken either the day of her predecessor's death (July 6) or that of her official proclamation as Queen (July 10) as the beginning of her short reign.
Lady Jane had a reputation as one of the most learned women of her day, and the historical writer Alison Weir describes her as one of "the finest female minds of the century".