Influenced by liberal revolutions occurring in Europe, the Liberal Revolution of 1820 started in Porto. The revolutionaries demanded the return of John VI of Portugal, who had transferred the Portuguese Court to the Portuguese colony of Brazil since the French invasions of Portugal, it also demanded a constitutional monarchy to be set up in Portugal. In 1822 a liberal constitution was accepted, partly through the efforts of the liberal assembly of Porto (Junta do Porto). When Miguel of Portugal took the Portuguese throne in 1828, he rejected this constitution and reigned as an absolutist monarch, initiating a civil war. Porto rebelled again and had to undergo a siege of eighteen months between 1832 and 1833 by the Miguelist army. After the abdication of king Miguel the liberal constitution was re-established. Porto is also called "Cidade Invicta" (English: Unvanquished City) after its resistance to the Miguelist army in the siege of Porto. Unrest by republicans led to a revolt in Porto on 31 January 1891. This would result ultimately in the creation of the Portuguese Republic in 1910.