Isabella II was the only female monarch of Spain in modern times. She came to the throne as an infant, but her succession was disputed by the Carlists, who refused to recognise a female sovereign, leading to the Carlist Wars

Carlist Wars

The Carlist Wars in Spain were the last major European civil wars in which contenders fought to establish their claim to a throne. Several times during the period from 1833 to 1876 the Carlists — followers of Infante Carlos and his descendants — rallied to the cry of "God, Country, and King" and...

. After a troubled reign, she was deposed in the Glorious Revolution

Glorious Revolution (Spain)

The Glorious Revolution took place in Spain in 1868, resulting in the deposition of Queen Isabella II.An 1866 rebellion led by General Juan Prim and a revolt of the sergeants at San Gil barracks, in Madrid, sent a signal to Spanish liberals and republicans that there was serious unrest with the...

 of 1868, and formally abdicated in 1870. Her son Alfonso XII became king in 1874.
Isabella was born in Madrid

Madrid

Madrid is the capital and largest city of Spain. The population of the city is roughly 3.3 million and the entire population of the Madrid metropolitan area is calculated to be 6.271 million. It is the third largest city in the European Union, after London and Berlin, and its metropolitan...

 in 1830, the eldest daughter of King Ferdinand VII of Spain, and of his fourth wife and niece, Maria Christina, who was a Neapolitan

Kingdom of the Two Sicilies

The Kingdom of the Two Sicilies, commonly known as the Two Sicilies even before formally coming into being, was the largest and wealthiest of the Italian states before Italian unification...

 Bourbon

House of Bourbon

The House of Bourbon is a European royal house, a branch of the Capetian dynasty . Bourbon kings first ruled Navarre and France in the 16th century. By the 18th century, members of the Bourbon dynasty also held thrones in Spain, Naples, Sicily, and Parma...

.