Thessalus was one of three sons of Jason and Medea (the other two being his twin Alkimenes as well as Tisander). When Medea decided to kill her own children as a form of vengeance for Jason leaving her, Thessalus escaped being murdered. Sometime later after the death of Akastus, Thessalus became king of Iolcus.
Jason & Medea
- One of Herakles' sons Thettalus is sometimes called Thessalus
- One of Haemon's sons is also named Thessalus