Thessaloniki is the second-largest city in Greece and the capital of Greek Macedonia, the administrative region of Central Macedonia and the Decentralized Administration of Macedonia and Thrace. Its nickname is a reference to its historical status as the Symvasilévousa or "co-reigning" city of the Eastern Roman Empire, alongside Constantinople. The municipality of Thessaloniki, the historical center, had a population of 325,182 in 2011, while the Thessaloniki Urban Area had a population of 788,952. and the Thessaloniki Metropolitan Area had 1,012,297 inhabitants in 2011.