Greeks founded Odessus there in the 6th Century BC. In 335 BC, the city surrendered to Alexander the Great. The Romans annexed Odessus in 15 AD. The 4th-century Aladzha Monastery, its cells and chapel carved out of the rock, overlooks the city from the north.
The city was named Varna and became part of the first Bulgarian empire in 681 AD. By the 13th Century, it was an important trade center for Genoa, Venice, and Dubrovnik, each of which had consulates in the city. In the 14th Century, the Port of Varna may have been the most important port between Constantinople and the Danube.
The Port of Varna fell to the Ottomans in 1391. In November 1444, one of the last battles of the Crusades was fought outside the city when 60 thousand Turks defeated 20 thousand European Crusaders, clearing the way for the fall of Constantinople in 1453. The Ottomans dominated the area for the next four centuries.
In 1854, the port was a base for Anglo-French troops during the Crimean War. Liberated from the Turks in 1878, the Port of Varna was ceded to Bulgaria. The 1866 Ruse-Varna railway and a 1899 railway to Sofia further supported growth. For a few years, the Port of Varna was on the route of the famous Orient Express. During the First Balkan War and World War I, Russian troops occupied the city. In World War II, Russia’s Red Army occupied the city and solidified communist rule in Bulgaria.