Isabella II of Spain was proclaimed queen, September 29, 1833.

Isabella II (10 October 1830 – 9 April 1904) was Queen of Spain from 1833 until her deposition in 1868. Being the only queen regnant in the history of unified Spain, her reign was marked by tumultuous events and political upheavals.

Early Life: The First Carlist War

Isabella II was born to King Ferdinand VII of Spain and Queen Maria Christina of the Two Sicilies, during a period of political turmoil. The aftermath of the French Revolution and Napoleon's invasion of the Iberian Peninsula ignited a bitter struggle between Spanish liberals and conservatives. In 1808, Napoleon forced Ferdinand VII to abdicate, plunging Spain into chaos and leading to the creation of a liberal constitution in 1812. However, when Ferdinand returned to power, he attempted to reinstate absolutism, causing further divisions within the nation.

Isabella's birth carried significant political consequences. Ferdinand VII, having no surviving children from his previous marriages, had no clear heir and his brother, Carlos, had anticipated inheriting the throne until Maria Cristina's pregnancy threatened his ambitions. He and his supporters argued that the Salic Law, which prohibited women from ruling, should apply. Nevertheless, Ferdinand had secretly revoked this law in 1829, allowing Isabella to ascend the throne.

When Ferdinand died on September 29, 1833, the Carlists, loyal to Carlos, refused to acknowledge Isabella's claim to the throne. Still, the Cortes declared Isabella II queen and appointed her mother, Maria Cristina, as regent. While France, Great Britain, and Portugal recognized Isabella's legitimacy, the Vatican and several conservative Catholic nations supported Carlos, sparking the First Carlist War. Isabella II's supporters, known as the Isabelinos, fought fiercely to defend her right to the throne, and the war ultimately ended in her favour in 1839.

Isabella's Reign

Despite Isabella II's reign officially beginning in 1833 when she was just three years old, her mother acted as regent until she came of age. Unfortunately, Maria Cristina provided inadequate guidance for the young queen, leaving her ill-equipped for the complexities of governance.

As Isabella reached puberty, political pressures mounted to select a suitable husband for her. She reluctantly married Francisco de Asís, who proved an unsuitable and disinterested spouse. Isabella's private life, marked by scandal, contrasted with her public image as a generous monarch. She forgave a significant state debt, donated to the poor, and survived assassination attempts, garnering public sympathy.

Throughout her rule, Isabella II relied heavily on military leaders like Espartero, Narváez, and O'Donnell, who had protected her monarchy during the Carlist War. The Spanish political system allowed the ruling party to manipulate election results, making it difficult to unseat the incumbent government except through pronunciamentos (military uprisings). However, the Liberal Union's formation in 1854 led to greater political stability. Between 1854 and 1866, Narváez and O'Donnell alternated as her chief ministers, aided by an economic boom during the mid-19th century, making this period the most prosperous of Isabella’s reign.

Troubles began to mount in 1863 when conservatives engineered the fall of O'Donnell's government and the exile of the Liberal Union. By 1866, Spain faced a crisis, with a depression affecting the country. Progressives sought power but were consistently denied access due to the conservatives' control of electoral processes. Moreover, Isabella's strong Catholic beliefs made it challenging for her to support some of the anticlerical measures advocated by the Progressives. As unrest grew, attempts at Progressive pronunciamentos failed, and Isabella increasingly became seen as an obstacle to modernization.

Abdication & Death

In April 1868, the "September Revolution," led by leaders like Prim, Topete, and Serrano, forced Isabella to flee to France and abdicate in favour of her son Alphonso in 1870. However, Spain's Cortes declared a permanent exclusion of the queen and her family from the country. As a result, Prince Amadeo of Savoy became king in 1870, but eventually abdicated in 1873, leading Spain into a republic.

In 1874, a pronunciamento in favour of Isabella's son, Alphonso XII, took place. Even though the latter’s early death in 1885 gave her the chance to return to the throne, Isabella had no inclination to rule again. Her line of succession was eventually succeeded by her posthumous grandson, Alphonso XIII, while she spent her later years in France until her death on April 10, 1904.

Isabella II's legacy is a complex and multifaceted one. Her reign, marked by political turmoil and instability, reflects the broader challenges facing Spain during the 19th century and saw the rise of political ideologies that would shape the country’s future.