Some 5,000 years ago Memphis today lying mainly in ruins approximately 15 miles (24 km) southwest of Cairo was a thriving metropolis; about 2,000 years ago the Romans occupied a town on the site of present-day Cairo called Babylon (later the Miṣr al-Qadīmah quarter).The seed from which contemporary Cairo later sprang was the town of Al-Fusṭāṭ, founded as a military encampment in 641 CE by ʿAmr ibn al-ʿĀṣ, an Arab general and administrator who brought Islam to Egypt. Successive dynasties added royal suburbs (including Al-ʿAskar, founded in 750 by the Umayyads, and Al-Qaṭāʾiʿ, founded in 870 by Aḥmad ibn Ṭūlūn) to the increasingly prosperous commercial and industrial port city of Al-Fusṭāṭ. Little remains of these early developments in the southern part of the city, except the tower of Trajan (dating to 130 CE), the mosques of ʿAmr ibn al-ʿĀṣ (founded in 641–642) and Aḥmad ibn Ṭūlūn (completed in 878), and the partially excavated mounds covering the site of Al-Fusṭāṭ.