Complex sentence: In 549 Totila advanced a third time against Rome, which he captured this time through the treachery of some of its starving defenders and this time the city was cleared of all human inhabitants for forty days.
Split into simpler sentences: In 549 Totila advanced a third time against Rome, which he captured this time through the treachery of some of its starving defenders. And this time the city was cleared of all human inhabitants for forty days.