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.

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.

He met the Norman and Lombard hosts on the Ofanto at the site of the famous defeat dealt the Romans by Hannibal in 216 BC: Battle of Cannae.

Though greatly honoured (he was given the empty title Duke of Apulia by the emperor), he died a broken man only two years later, just after Pope Benedict arrived in Bamberg at Eastertide to discuss an imperial response to the Byzantine victories.