Tellus
A timeline written by Tony Jones; he wrote it in response to a challenge to come up with the most unusual and original AH scenario for roleplaying purposes he could think of.
A world where the Roman and Chinese empires achieve sustained contact after the 2nd Century AD. Although technology advances much faster in this world (reaching OTL 2000 level by 1150), humanity is nearly destroyed in a catastrophic total war between Rome (and its ally India) and China known as the “Nex” in this world's 15th century. It takes a long time for the world to put itself back together from this disaster, and by the end of the 20th century, the world stage is very different. Rome, China and India are still powers, but most of their former colonies have become independent nations in the centuries recovering from the Nex. The 'current' year is 2335 AD (3088 AUC by the Roman calendar). The Chinese government is secretly controlled by the last of the A.I.s remaining from the advanced period before the Nex, though in other respects, by 2335, the world has recovered to the advanced state it was in the 1400s.
You can read this timeline here, at Tony's AH website.
(Not to be confused with now-banned AH.com member Tellus.)