Ephesus (/ˈɛfəsəs/; Greek: Ἔφεσος Ephesos; Turkish: Efes; ultimately from Hittite Apasa) was an ancient Greek city on the coast of Ionia, three kilometres southwest of present-day Selçuk in İzmir Province, Turkey. It was built in the 10th century BC on the site of the former Arzawan capital by Attic and Ionian Greek colonists. During the Classical Greek era it was one of the twelve cities of the Ionian League.

The city flourished after it came under the control of the Roman Republic in 129 BC. According to estimates, Ephesus had a population of 33,600 to 56,000 people in the Roman period, making it the third largest city of Roman Asia Minor after Sardis and Alexandria Troas.
The city was famed for the Temple of Artemis (completed around 550 BC), one of the Seven Wonders of the Ancient World. In 268 AD, the Temple was destroyed or damaged in a raid by the Goths.It may have been rebuilt or repaired but this is uncertain, as its later history is not clear. Emperor Constantine the Great rebuilt much of the city and erected new public baths. Following the Edict of Thessalonica from Emperor Theodosius I, what remained of the temple was destroyed in 401 AD by a mob led by St. John Chrysostom. The town was partially destroyed by an earthquake in 614 AD. The city’s importance as a commercial center declined as the harbor was slowly silted up by the Küçükmenderes River.