In Greek mythology, King Cyzicus or Kyzikos (Ancient Greek: Κυζίκου) was the ruler of the Dolionians, a tribe that inhabited the southern shore of the Propontis (the Sea of Marmara). He gave his name to a city of the same name, Cyzicus, his capital.
Cyzicus's parentage is given as Aeneus by Aenete (or Aenippe), daughter of Eusorus; or else Eusorus is given as his father. King Cyzicus is sometimes referred to as a Thessalian migrant (hence his hospitality to the Argonauts, many of whom hailed from Thessaly, including Jason himself). The name Aeneus recalls the Thracian city of Aenus, although Aeneus is said to be the son of Apollo and Stilbe, a daughter of the Thessalian River Peneus.. Her wife was called Cleite, daughter of Merops of Percote, others say that she was Larissa, daughter of Piasus.
After the departure of the Argonauts in Lemnos, they landed in the island of the Doliones of whom Cyzicus was the king. He welcomed the Argonauts on their journey to Colchis and received them with generous hospitality. But after their departure, a storm drove them back to the Cyzicene coast at night. With neither the Argonauts nor King Cyzicus recognizing one another, each mistook the other as an enemy and battle ensued. The Doliones thought they were Pelasgian army who constantly harassed them.
The enemy have seized the harbour, our hold foes the Pelasgians have returned!” Men’s rest was broken; the god Pan had driven the doubting city distraught, Pan fulfilling the cruel commands of the Mygdonian Mother [i.e. Cybele], Pan lord of the woodlands and of war, whom from the daylight hours caverns shelter; about midnight in lonely places are seen that hairy flank and the soughing leafage on his fierce brow.