Romanos was detained at Constantinople in 1070, while he dealt with many outstanding administrative issues, including the imminent fall of Bari into Norman hands. They had been besieging it since 1068, but it had taken Romanos two years to respond. He ordered a relief fleet to set sail, containing sufficient provisions and troops to enable them to hold out for much longer. The fleet was intercepted, however, and defeated by a Norman squadron under the command of Roger, the younger brother of Robert Guiscard, forcing the final remaining outpost of Byzantine authority in Italy to surrender on 15 April 1071.