Thessaloniki, (Greek: Θεσσαλονίκη), is Greece's second-largest city and the capital of the Greek region of Macedonia. Thessaloniki is commonly called the 'ΣυμπÏωτεÏουσα' 'Symprotevousa' (lit. co-capital) of Greece since the National Schism, due to both its long history and its strategic geographic and economic importance. According to official data, the Thessaloniki Urban Area curves round the Thermaic Gulf for approximately 17 km; it comprises 13 municipalities and according to the 2006 census it has a population of 809,457.