The years of political struggle between the conservative authoritarian absolutists and the progressive constitutionalist Liberals over the issue of royal succession, lasting from 1828 to 1834, was a complex period in Lisbon's history. In 1828, Prince Michael, whom the absolutists wanted to rule Portugal as an absolute monarch, returned from exile in Vienna. Conservative politicians, clergymen and aristocratic supporters of Queen Carlota manipulated political developments and proclaimed him king, starting a civil war against the forces of the Liberal constitutionalists who supported his brother, Emperor Peter I of Brazil. Peter's forces won the war in 1834 and he became Pedro IV of Portugal, but the new Constitution as promulgated was more conservative than expected by the people. However, it did present some liberal reforms, such as restoration of freedom of the press, mandatory education, abolishment of the slave trade in the African colonies, extinction of the religious orders and confiscation of their convents, as well as the expropriation of many other properties of the Catholic Church, which had supported the Miguelists. The Liberals of Lisbon soon became disillusioned with Pedro and formed new political conspiracies. On 9 September 1836, the politicised population, many of them petty bourgeois and literary intellectuals, joined with the National Guard to drive the "Cartistas" (Chartists) from power and forced Queen Maria II to reinstate the 1822 Constitution. Members of the government installed following this revolution were called "Setembristas", after their short-lived movement, the "Setembrismo", which was launched in September. The absolutists attempted a coup in 1836, and again in 1837. The country was divided into two opposing radical groups that refused to engage in a dialogue. Seeing opportunity in this chaotic state of affairs, the great northern European powers planned the division of its provinces and colonies.