Although the last invasions and last large scale conflict between the two powers lasted less than two years, the third Norman invasions came closer still to taking Constantinople. Then Byzantine Emperor Andronicos Komnenos had allowed the Normans to go relatively unchecked towards the Tessalonica. While David Komnenos had made some preparations in anticipation of the encroaching Normans, such as ordering reinforcement of the cities walls' and assigning four divisions to the cities' defense, these precautions proved insufficient. Only one of the four divisions actually engaged the Normans, resulting in the city being captured with relative ease by Norman forces. Upon gaining control of the city Norman forces sacked Thessalonica. The following panic resulted in a revolt placing Isaac Angelus on the throne. In the aftermath of the fall of Andronicus, a reinforced Byzantine field army under Alexios Branas decisively defeated the Normans at the Battle of Demetritzes. Following this battle Thessalonica was speedily recovered and the Normans were pushed back to Italy.