Stone detail in the Roman Theatre in Alexandria. The Roman Theatre was built in the 4th century AD and it remained in use until about the 7th century AD, or about the time of the Arab invasion. It was discovered during the 1960's when a government building was planned for this location, over the ruins of a Napoleonic fort that had earlier been destroyed. However, during excavation the ruins of the Roman Theatre were found. A Polish team was responsible for its excavation. It was the first, and so far the only one discovered in a city which, according to an ancient source, once had four hundred of them.