Warlord Games has a free version of its Blood Red Skies WWII Aircraft Rules.
I did not get far into the Game of Thrones book before I recognized the parallels to the Wars of the Roses. This video, which features author George RR Martin, discusses the historical parallels behind Game of Thrones. Martin said that his strategy was to take historical events and "dial them up to 11."
Robert Baratheon, for example, parallels Edward IV. Tyrion Lannister as Richard III. Sansa Stark as Elizabeth of York. Ned Stark as Richard, Duke of York. And so on.
The video above does a pretty good job of illuminating the real history behind Game of Thrones.
Fusilier is a set of free wargames rules for the the flintlock era.
The author writes:
The Flintlock Era
Fusilier is a wargames system designed for the period 1700 to 1815.
The system is designed to be used with any scale of figures. There is no formal figure scale, the unit sizes being dictated by the base sizes, which in turn are based on the frontages of the prototype units. An infantry battalion might be, for example, ten 25mm figures, twenty 15mm figures or fifty 5 mm figures. The ground scale is 1 mm = 1 metre