The Great Khan Game, by Tom Wham and Richard Hamblen, is an underrated gem IMHO. It is a combination card & board game whose mechanics would work wonderfully as a historical game. Unfortunately it was manhandled into a swords & sorcery setting and packaged as a AD&D scenario (this was misrepresentation by TSR and put off the game's natural audience while probably making most of the people who bought it feel ripped off.)

The game uses a rummy-style draw and discard mechanism. The cards represent individuals and military forces in the various countries on the board. Players expand their influence on the board by taking over other nations either through Risk-style combat or by using their Rummy skills by revealing a stronger set in a given nation's suite and that country's existing owner has on the table.

The rummy/wargame mechanics simulate internal politics in global conflict nicely. The game, unfortunately, was spoilt by the addition of magic combat which seems to have been tacked on to enable TSR to link it to AD&D. The game has a Napoleonic or Victorian historical feel and it's a pity nobody has redone it without "The Magic Isle of Broddick" to unbalance it.