What would be some interesting historical points of divergence? Realistic: - Neanderthals survive - A Roman legion (or several) stays behind in Britannia - Harold beats William in the Battle of Hastings, 1066. - Henry V does not die prematurely at age 35 - Henry VIII is granted a divorce by the Pope - Britain realises the power of aircraft carriers in the 1930s, as the USA and Japan did Fantastical: - Nuclear bombs not possible - The existence of a mid-Atlantic micro-continent, settled by the Romans. Part 1, Part 2. - Habitable Antarctica - Full military schematics, including theoretical underpinnings and production methods, of X period sent back in time to Y period. - Deposits of naturally occurring advanced materials like carbon nanotubes, graphene, etc - Existence of a range of biological products with great value, similar to the utility of penicillin. The plants/organisms which produce them are geographically limited. Medical, educational, military, industrial applications of great power.