The Battle of Monte Porzio (also called the Battle of Tusculum) was fought on 29 May 1167 between the Holy Roman Empire and the Commune of Rome. The communal Roman army, which one historian has called the "greatest army which Rome had sent into the field in centuries", was defeated by the forces of the Emperor Frederick Barbarossa and his local allies, the Counts of Tusculum and the ruler of Albano. Comparing its effect on the city of Rome, one historian has been called Monte Porzio the "Cannae of the Middle Ages".[2]