Isabella II, also known as the Queen of Sad Mischance and the Traditional Queen, was Queen of Spain from 29 September 1833 until 30 September 1868.
Shortly before her birth, the King issued a Pragmatic Sanction to ensure the succession of his firstborn daughter, due to his lack of a son. She came to the throne a month before her third birthday, but her succession was disputed by her uncle the Infante Carlos, whose refusal to recognize a female sovereign led to the Carlist Wars. Under the regency of her mother, Spain transitioned from an absolute monarchy to a constitutional monarchy adopting the Royal Statute of 1834 and Constitution of 1837.
Her effective reign was a period marked by palace intrigues, back-stairs and antechamber influences, barracks conspiracies, and military pronunciamientos.
She came to be known by the sobriquets of the Traditional Queen, and the Queen of Sad Mischance.
She was deposed in the Glorious Revolution of 1868, and formally abdicated in 1870. Her son, Alfonso XII, became king in 1874.