John, one of the officers highest in rank under Belisarius, had pressed on to Rimini, contrary to the instructions of his chief, leaving in his rear the difficult fortress of Osimo (Auximum) untaken.
But his friend Narses so insisted on the blow to the reputation of the imperial arms which would be produced by the surrender of Rimini that he carried the council of war with him, and Belisarius had to plan a brilliant march across the mountains, in conjunction with a movement by the fleet, whereby Rimini was relieved while Osimo was still untaken.
Notwithstanding his opposition, the progress of the Vandals was rapid, and by May 430 only three cities of Roman Africa - Carthage, Hippo and Cirta - remained untaken.