Yeşilköy (jeˈʃilcœj; meaning "Green Village"; prior to 1926, San Stefano or Santo Stefano Ágios Stéfanos, Ayastefanos) is an affluent neighbourhood (mahalle) in the municipality and district of Bakırköy, Istanbul Province, Turkey. Its population is 25,039 (2022). on the Marmara Sea about west of Istanbul's historic city centre. Prior to the rapid increase of Istanbul's population in the 1970s, Yeşilköy was a secluded village and sea resort. The original name, San Stefano, in use until 1926, derives from a legend: in the early 13th century, the ship carrying Saint Stephen's relics to Rome from Constantinople, sacked by the crusaders of the Fourth Crusade, was forced to stop here because of a storm. The relics were taken to a church until the sea calmed, and this gave the name to the church and to the place. In 1926, the village was named Yeşilköy which means "Green Village" in Turkish. It is believed that the writer Halit Ziya Uşakligil who lived there at the time gave this new name to the village. It is still referred to as Сан Стефано in Bulgarian (bg). In 1203, the beach of Agios Stefanos had been the site of disembarkation of the Latin army of the Fourth Crusade, which would conquer Constantinople the following year. In the 19th century, the whole village was owned by the powerful Armenian Dadian family. During the Crimean War, French forces were stationed here and built one of the three historic lighthouses of Istanbul still in use. San Stefano was where in 1878 the Russian forces halted their advance towards Constantinople at the end of the Russo-Turkish War and was the location where the Treaty of San Stefano was signed between the Russian and Ottoman Empires. In 1909, the decision to send Sultan Abdülhamid II into exile to Thessaloniki was taken by the members of the Committee of Union and Progress at the yacht club of San Stefano. On 10 July 1894, San Stefano – as with the whole Marmara region of Constantinople – was hit by a strong earthquake, followed by a tsunami.