Albergaria de Sousa remained at the Royal Court until the beginning of 1820, then traveled to Lisbon, arriving in Portugal as the Liberal Revolution began in Porto. He encountered the formation of the Constituent Cortes of 1820, a parliamentary group debating Portugal's form of government in the post-Napoleonic Era. Albergaria de Sousa became involved in the politics of Lisbon, becoming a member of the "Sociedade Patriótica Filantropia" ("Patriotic Philanthropic Society") and congregating with a likeminded group of Azoreans who were participating in the Cortes. He ultimately assumed this Azorean group's leadership and helped instill in it the notion that the Portuguese Constitution of 1822 could introduce a new democratic government in the Azores that would abandon the old colonial administration and system imposed by the Captaincy-General of the Azores.