Melus (also Milus or Meles, Melo in Italian) (died 1020) was a Lombard nobleman from the Apulian town of Bari, whose ambition to carve for himself an autonomous territory from the Byzantine catapanate of Italy in the early eleventh century inadvertently sparked the Norman presence in Southern Italy.
Melus and his brother-in-law Dattus rebelled in 1009 and quickly took Bari itself. In 1010, they took Ascoli and Troia, but the new catapan, Basil Mesardonites, gathered a large army, and on 11 June 1011 Bari fell. Melus fled to the protection of Prince Guaimar III of Salerno and Dattus to the Benedictine abbey of Montecassino, where the anti-Greek monks, at the insistence of Pope Benedict VIII, gave him a fortified tower on the Garigliano. Melus' family, however, were captured and carted off to Constantinople.
In 1016, according to the Norman chronicler William of Apulia, Melus went to the Shrine of Saint Michael at Monte Gargano to intercept some Norman pilgrims. There he petitioned Rainulf Drengot and a band of Norman exiles to aid in his rebellion, assuring them of the ease of victory and the abundance of spoils. By 1017, Norman adventurers were already heading south. They joined with the Lombard forces under Melus at Capua and marched into Apulia immediately, trying to catch the Byzantines off-guard. Successful in an encounter in May on the banks of the Fortore against forces sent by the catapan Leo Tornikios Kontoleon, they had seized all the territory between the Fortore and Trani by September and were ravaging Apulia; in October, however, they experienced a stunning reverse.