His purpose evidently was to avoid all conflict which would risk a reduction of the Gothic army, and by patient blockade to starve the Romans into surrender.
He could not surround the city, with its circuit of twelve miles; he could not keep ceaseless watch upon the sixteen gates and the numerous posterns.

King Vitiges, in his attempt to do so, had suffered terrible losses.

It was inevitable that folk should pass in and out of Rome.

But from inland no supplies could be expected by the besieged, and any ship sailing up to Portus would have little chance of landing its cargo safely.

Before long, indeed, this was put to proof.