Twin brother of Sanasar; co-founder of Sassoun in the Sasna Tsřer epic. Less narratively-developed than Sanasar in the standard recension; the post-founding narrative-trajectory varies — some recensions have him depart eastward after a quarrel with Sanasar to found a separate dynastic line, others have him return to participate in later Sassoun episodes. The twin-name pair Sanasar-Baghdasar preserves the Old Testament Sanasar-Belshazzar onomastic complex (2 Kings 19:37 + Daniel 5), reflecting medieval-Armenian-Christian liturgical-Biblical transmission of Mesopotamian royal names into the Sassoun heroic-epic frame.