https://www.alternatehistory.com/discussion/showthread.php?t=108131
This in an excellent timeline where both the Eastern and Western Empires fall in the fifth century. In it a Christian-Greco-Roman-Egyptian sucessor state is founded by a Roman revolt. At the height of it's power it covers Egypt, Syria, and about half of Asia Minor. Currently they're just recovering from a war with TTL's verson of Islam which saw the Arabs giving up before taking Suez do to internal problems.