Chatzon (Greek: Χάτζων[1][2]) or, in some modern Slavic studies, Hacon (Хацон),[3][4] was a Slavic chieftain (έξαρχος Σκλαβίνων 'exarch of the Sclaveni' in the Greek sources) who, according to Book II of the Miracles of Saint Demetrius, led a coalition of Slavic tribes to attack the Byzantine city of Thessalonica in 615.[1][2]
The Slavs with their families encamped in front of the city walls and even launched an attack by sea, but the latter failed due to a storm (attributed by the Byzantines to the intervention of Saint Demetrius, Thessalonica's patron saint) which sunk many of the Slavs' logboats, after which the siege was lifted.[1][2] Chatzon himself was allowed to enter the city during negotiations shortly after; however, the urban mob rioted at the instigation of the mothers of those slain during the siege and killed him, despite the city leaders' attempts to hide him.[1][2] After this, the Slavs asked for the help of the Avars, resulting in the unsuccessful month-long siege of the city by the combined Avar and Slavic forces in 617/618.[1][2][5]