Pergamon
Pergamon lies on the north edge of the Caicus plain in the historic region of Mysia in the northwest of Turkey. The Caicus river breaks through the surrounding mountains and hills at this point and flows in a wide arc to the southwest. At the foot of the mountain range to the north, between the rivers Selinus and Cetius, there is the massif of Pergamon which rises 335 metres above sea level. The site is only 26 km from the sea, but the Caicus plain is not open to the sea, since the way is blocked by the Karadağ massif. As a result, the area has a strongly inland character. In Hellenistic times, the town of Elaia at the mouth of the Caicus served as the port of Pergamon. The climate is Mediterranean with a dry period from May to August, as is common along the west coast of Asia Minor.
Pergamon
The earliest mention of Pergamon in literary sources comes from Xenophon's Anabasis, since the march of the Ten Thousand under Xenophon's command ended at Pergamon in 400/399 BC. Xenophon, who calls the city Pergamos, handed over the rest of his Greek troops (some 5,000 men according to Diodorus) to Thibron, who was planning an expedition against the Persian satraps Tissaphernes and Pharnabazus, at this location in March 399 BC. At this time Pergamon was in the possession of the family of Gongylos from Eretria, a Greek favourable to the Achaemenid Empire who had taken refuge in Asia Minor and obtained the territory of Pergamon from Xerxes I, and Xenophon was hosted by his widow Hellas.