In the first Restoration governments, he was successively Secretary General of the Ministry of Justice, a member of the Council of State and Director of Departmental and Communal Administration at the Ministry of the Interior. From 1817 onwards, together with Royer-Collard and a few political friends the small group of «doctrinaires», attached to a liberal reading of the Charter. When the ultra-royalists came to power in 1820, he was placed in opposition and dismissed from the Conseil d'État. Two years later, his history course at the Sorbonne on the origins of representative government was suspended. During these two years, he published four opuscules sharply critical of the Ministry, which pushed him further and further to the left. From 1827, at the head of the «Aide-toi le Ciel t'aidera» society, Guizot emerged as one of the main leaders of the opposition to Charles X's policies. At the same time, he undertook important historical works, initially Essays on the history of France (1823), followed by the first two volumes of the’History of the English Revolution (1826-1827). The triumphant reopening of his course in 1828 was a public event attended by liberal youth.