In Greek mythology, Cyzicus (Ancient Greek Κύζικος) is king of the Doliones on the Propontis who receives the Argonauts with hospitality, then dies fighting them by night when a storm drives the Argo back unrecognized. The city of Cyzicus takes his name; his bride Cleite hangs herself in grief.
Adapted from Wikipedia, "Cyzicus (mythology)" · CC BY-SA 4.0
I.Hospitality and fatal return
Parentage varies: Aeneus by Aenete (or Aenippe) daughter of Eusorus, or Eusorus himself as father; his wife is Cleite daughter of Merops of Percote (or Larissa daughter of Piasus). After Lemnos the Argonauts land among the Doliones; Cyzicus welcomes them as a Thessalian-linked host.
A storm drives them back by night. Neither side recognizes the other; the Doliones take the strangers for Pelasgian raiders. Cyzicus falls to Jason (or Heracles). Dawn reveals the mistake: three days of mourning, a mound, armed circuits, rites and games follow. Valerius Flaccus adds that Cybele engineered the error because Cyzicus had slain one of her lions.
II.Homonym note
The atlas id cyzicus-dolion is the mythic Dolionian king. The historical and archaeological city is the place named for him, not a second character node.