Xanthos, the capital city of the Lycian Federation, was built in the valley of the Xanthos River. There are no definitive records of the exact date of its founding. As mentioned in The Iliad, King Sarpedon crossed the Xanthos River with his soldiers. Like other Lycian cities, Xanthos was an independent state until the Persian invasion in 545 BC.
When the city was besieged by the Persians, the residents bravely defended it. However, realizing they could not resist the invasion, King Harpagos and the people refused to submit to Persian rule. The men of Xanthos gathered their wives, children, and possessions in the acropolis, set fire to everything, then rushed out fighting to die to the last man in an act of mass suicide.
About 80 families who were away from the city during these tragic events returned and rebuilt Xanthos.
In 43 BC, during the Roman Civil Wars, Brutus attempted to take control of Xanthos. As before, the Xanthians chose mass suicide over submission.
The Romans later took control of Lycia and repaired the destroyed city. During the Eastern Roman Empire under Antonius, who defeated Brutus, Xanthos regained its independence. Following two catastrophic earthquakes in subsequent years, the city began to decline in importance.
With the spread of Christianity and the accompanying social and cultural changes, Xanthos became an episcopal center during the Byzantine period. The city was eventually abandoned following Arab raids.
The most significant ruins remaining from ancient Xanthos are the Roman theatre and royal tomb monuments. Important reliefs from the tomb monuments are displayed at the British Museum.