Complex sentence: The last Roman-Persian Wars ended in 627, with Emperor Heraclius finally emerging victorious after his successful campaign in Mesopotamia against the Persians, while Mohammad united the Arabs under the banner of Islam.
Split into simpler sentences: The last Roman-Persian Wars ended in 627, with Emperor Heraclius finally emerging victorious after his successful campaign in Mesopotamia against the Persians. Meanwhile Prophet Mohammad united the Arabs under the banner of Islam.