Hundred Thousand Sons of Saint Louis in the context of "Charles Albert of Sardinia"

Ferdinand VII (Spanish: Fernando VII; 14 October 1784 – 29 September 1833) was King of Spain during the early 19th century. He reigned briefly in 1808 and then again from 1813 to his death in 1833. Before 1813, he was known as el Deseado (the Desired), and after, as el Rey Felón (the Criminal King).

Born in Madrid at El Escorial, Ferdinand was heir apparent to the Spanish throne in his youth. Following the 1808 Tumult of Aranjuez, he ascended the throne. That year Napoleon overthrew him; he linked his monarchy to counter-revolution and reactionary policies that produced a deep rift in Spain between his forces on the right and liberals on the left. Back in power in December 1813, he re-established the absolutist monarchy and rejected the liberal constitution of 1812. A revolt in 1820 led by Rafael del Riego forced him to restore the constitution, starting the Liberal Triennium, a three-year period of liberal rule. In 1823, the Congress of Verona authorised a successful French intervention, restoring him to absolute power for the second time. He suppressed the liberal press from 1814 to 1833, jailing many of its editors and writers.

The Trienio Liberal, ([ˈtɾjenjo liβeˈɾal], lit. 'Liberal Triennium') or Three Liberal Years, was a period of three years in Spain between 1820 and 1823 when a liberal government ruled Spain after a military uprising in January 1820 by the lieutenant-colonel Rafael del Riego against the absolutist rule of Ferdinand VII.

It ended in 1823 when, with the approval of the crowned heads of Europe, a French army invaded Spain and reinstated the King's absolute power. This invasion is known in France as the "Spanish Expedition" (expédition d’Espagne) and in Spain as the "Hundred Thousand Sons of Saint Louis."