Lucius Tiberius (sometimes Lucius Hiberius, or just simply Lucius; also Thereus in Claris et Laris) is a Western Roman procurator or emperor from Arthurian legend, who is killed in a war against King Arthur. First appearing in Geoffrey of Monmouth's Historia Regum Britanniae, Lucius also appears in later, particularly English literature such as the Alliterative Morte Arthure and Thomas Malory's Le Morte d'Arthur. The motif of a Roman Emperor defeated by Arthur appears in the Old French literature as well, notably in the Vulgate Cycle. In the narrative, after Arthur liberates Gaul from Roman tribune Frollo, a Romanized German who tried to take advantage of Arthur's war with Claudas, word of his great deeds reaches Rome itself. Lucius demands that Arthur pay him tribute and recognize him as his sovereign, as had been done by Britain since the time of Julius Caesar. Arthur refuses on the basis that the British kings Belinus and Brennius had defeated Rome in the past. In retaliation, Lucius gathers heathen armies from Spain and North Africa and invades the lands of Arthur's allies on the continent in Brittany. Rome is supposed to be the seat of Christianity, but it is more foreign and corrupt than the courts of Arthur and his allies. He is also mentioned as married to daughter of one of his pagan allies, a Middle Eastern ruler named only just as the Emir (Amiraut), in the poem Didot Perceval. Arthur and the other kings allied with him hurry across the English Channel against the Roman threat. In the Historia, the war begins when Lucius' nephew (uncle in the Alliterative Morte Arthure), Gaius Quintilianus, is killed by Gawain after he insults the Britons. Lucius himself then dies by unknown hand as the armies of Rome and the Empire's Germanic allies are conquered by Arthur's forces. In Malory's version, following that of the Alliterative Morte Arthure, Lucius is killed in an intense personal duel with Arthur himself during their great battle; he manages to wound Arthur before getting decapitated with Excalibur. Arthur then sends the bodies of Lucius and other slain nobles back to Rome, telling them this is the only tribute he will send them. In French La Mort le Roi Artu, however, the Roman leader is portrayed more sympathetically. The figure of Lucius is clearly fictional, though whether Geoffrey took the character from tradition or completely created him for propagandist purposes is