Egypt (Latin: Aegyptus [ae̯ˈɡʏptʊs]; Koinē Greek: Αἴγυπτος Aígyptos [ɛ́ːɡyptos]) was a subdivision of the Roman Empire from Rome's invasion of the Ptolemaic Egyptian Kingdom after the battle of Alexandria in 30 BC to its loss by the Byzantine Empire to the Islamic conquests in AD 641. The province encompassed most of modern-day Egypt except for the Sinai, and was bordered by the provinces of Crete and Cyrenaica to the west and Judea, later Arabia Petraea, to the East. Egypt came to serve as a major producer of grain for the empire and had a highly developed urban economy. Aegyptus was by far the wealthiest Eastern Roman province, and by far the wealthiest Roman province outside of Italy. The population of Roman Egypt is unknown, although estimates vary from 4 to 8 million. In Alexandria, i