Egypt and Memphis were taken for Persia by king Cambyses in 525 BC after the Battle of Pelusium. Under the Persians, structures in the city were preserved and strengthened, and Memphis was made the administrative headquarters of the newly conquered satrapy. A Persian garrison was permanently installed within the city, probably in the great north wall, near the domineering palace of Apries. The excavations by Flinders Petrie revealed that this sector included armouries. For almost a century and a half, the city remained the capital of the Persian satrapy of Egypt ("Mudraya"/"Musraya"), officially becoming one of the epicentres of commerce in the vast territory conquered by the Achaemenid monarchy.