Thessaloniki, the most important city of Macedonia, was built on the Aegean coast by King Kassandros. It was named after his wife Thessaloniki [=victory over the Thessalians], the step-sister of Alexander the Great. In Hellenistic and Roman times the city grew into a major port and urban centre. In the Byzantine era it gained the honorary title of "Symvasilevousa" [the co-reigning city] and during five centuries of Ottoman rule it developed into the major emporium of the Balkans. As an integral part of the Greek state since October 1912 it came to be known a the "symprotevousa" [=co-capital] of Greece. During 20 centuries of being a leading centre in multi-ethnic and multi-cultural empires it provided rich ground for the cross-fertilisation and peaceful co-existence of various cultures.