The Siege of Trsat (Croatian: Opsada Trsata) was a battle fought over possession of the town of Trsat (Latin: Tarsatica) in Liburnia, near the Croatian–Frankish border. The battle was fought in the autumn of 799 between the defending forces of the Dalmatian Croatia under the leadership of Croatian duke Višeslav and the invading Frankish army of the Carolingian Empire led by Eric of Friuli.