30. Ancient Rome
The civilization began as an Italic settlement in the Italian peninsula,
dating from the 8th century BC, that grew into the city of Rome and
which subsequently gave its name to the empire over which it ruled
and to the widespread civilisation the empire developed. The Roman
empire expanded to become one of the largest empires in the ancient
world, though still ruled from the city, with an estimated 50 to
90 million inhabitants (roughly 20% of the world's population) and
covering 5.0 million square kilometres at its height in AD 117.
