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 η Συμπρωτεύουσα (Symprotévousa), literally "the co-capital", a reference to its historical status as the Συμβασιλεύουσα (Symvasilévousa) or "co-reigning" city of the Eastern Roman (Byzantine) Empire, alongside Constantinople.