Trienio Liberal
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." == Revolution of Cabezas de San Juan == King Ferdinand VII provoked widespread unrest, particularly in the army, by refusing to accept the liberal Spanish Constitution of 1812.