The capital city of Londonium was an ethnically diverse city with inhabitants from across the Roman Empire, including natives of Britannia, continental Europe, the Middle East, and North Africa. There was also cultural diversity in other Roman-British towns, which were sustained by considerable migration, both within Britannia and from other Roman territories, including North Africa, Roman Syria, the Eastern Mediterranean, and continental Europe. Of Roman Britain's estimated population of three million, the urban population was about 240,000 people, with Londinium having an estimated 60,000 people. However, after Britannia ceased to be a functional Roman province, many of the urban areas collapsed and the overall population may have declined by as much as two million.