Historical and not so historical people made an impact in either the real world, or the minds of the players. Contradicting historical or perceived historical situations is the discresion of the GM. The information presented here is mostly summarized from Wikipedia or some other references.

John van Duyn Soutworth: The age of Sails (1968)
Denison, History of Cavalry from the Earliest Times (1877)
Montross - War though the ages (1944)