Subtitled 'A World Without Islam', with a divergence in the murky period of Late Antiquity. Currently awaiting a reboot in a Version 2.0 by the author, Huehuecoyotl. TL here.
The Aksumite assault on Mecca in 570 CE succeeds, and OTL's great religious tradition of Islam never comes to be. The resulting world diverges rapidly from our own, as different faiths take its place, and new empires rise to reclaim the glories of Classical Antiquity.