Origin: 1325–75;Middle English < Late Latinimperiālis, equivalent to Latinimperi(um) imperium + -ālis-al1; replacing Middle Englishemperial < Middle French < Late Latin, as above
late 14c., "having a commanding quality," from O.Fr. imperial (12c.), from L. imperialis "of the empire or emperor," from imperium (see empire). Meaning "of or pertaining to an empire" (especially the Roman) is from late 14c.