The flag traces back to the coat of arms of the medieval Babenberg dynasty, a silver band on a red field (in heraldry: "Gules a fess Argent"). The origin of the "Bindenschild" has not been conclusively established, it possibly derived from the Styrian margraves of the Otakar noble family, who themselves may have adopted the colours from the descendants of the Carinthian duke Adalbero (ruled 1011–1035), a scion of the House of Eppenstein extinct in 1122. However, the Babenberg margrave Leopold III of Austria (1095–1136) had already been depicted with a triband shield in 1105.