Salonica, or Salonika,(modern Greek:Thessaloníki), Greece, the nation's second largest city and the chief city of the Macedonia region of Greece. Salonica lies at the head of the Gulf of Therma, an inlet of the Aegean Sea, and is a major port. It is also the commercial, industrial, and transportation center of northern Greece.
Salonica has numerous historical landmarks, including a 2nd-century Roman forum, a 4th-century Roman arch, and many early Christian churches. The White Tower, the last remnant of the city's 15th-century fortifications, stands on the waterfront. The old Turkish quarter was the birthplace of Kemal Atatürk, founder of modern Turkey. Salonica has two universities and an archeological museum, which houses treasures of the ancient kingdom of Macedonia.
Salonica was founded about 315 B.C. on the site of ancient Therma by Cassander, king of Macedonia. The city later became the capital of the Roman province of Macedonia. It steadily gained in importance and under Byzantine rule was second only to Constantinople. It was the capital of the Kingdom of Thessalonica, part of the Latin Empire established by Franks of the Fourth Crusade, from 1204 until 1222. The city was restored to the Byzantine Empire by the Nicaeans in 1261, after a struggle with the Greeks. Salonica fell to the Turks in 1430 and remained part of the Ottoman Empire until the Balkan War of 1912, when it became part of Greece.