Though its authenticity is doubted, a blade named Colada and traditionally identified with that of El Cid, with the addition of a 16th-century hilt, is preserved in the Royal Palace of Madrid. According to Sebastián de Covarrubias, Colada clearly means a sword made from "acero colado", a process of alloyed steel without impurities. As Tizona, Colada appears in the epic poem Cantar de mio Cid as a sword that frightens unworthy opponents if wielded by a brave warrior. El Cid gives the sword to Martín Antolínez as a present, and he uses it in the duel against the infante Diego González.