BEIRUT, Lebanon — After months of fierce bombardment and failed diplomacy, the Syrian government began removing residents from the last rebel-held districts in the city of Aleppo on Thursday, a process that solidifies President Bashar al-Assad’s control over the country’s largest city.

Cold, hungry and carrying satchels and children, about 1,000 people, some of them wounded, boarded green buses and ambulances that carried the first batch of evacuees out of the rebel enclave. A second group of more than 1,000 people departed later, and a third left after nightfall.

Mr. Assad hailed the evacuation in a video released by his office, saying the “liberation” of Aleppo would serve as a historical watershed, like the birth of Christ, the revelation of the Quran, the collapse of the Soviet Union and the two world wars.