Found a pretty cool board game at a neighborhood yard sale (the second best place to find great old games no one knows about anymore--thrift stores are still the best): Lionheart from Parker Brothers.
I had a friend back in my teaching days that was into historical tabletop gaming in a big way. That's where people spend thousands of dollars and countless hours over many years buying and hand-painting small, historically accurate lead replicas of soldiers, archers, artillery and the like from whatever their favorite historical wars are--then they line them up on giant tables decorated with scale-sized trees, grass, hills, rivers, bridges, buildings and more and reenact historical battles, or make up their own new conflicts.
I could never justify the time or expense of getting so involved in this hobby, but I did play a few engagements with my friend and had a surpringly good time getting pummelled.
Lionheart is a much-simplified version of these sprawling, unweildy, multi-hour games. The battlefield is the size of a normal board game. The units are composed of 1 to 4 plastic soldiers, no meticulous hand-painting required. Players put on the indicated number of soldiers for each type of unit: 1 king, 2 knights, 4 archers or 4 foot soldiers per square base. These units are arranged in a face-off, and the battle begins. First to kill the king or his oppoenents entire army wins.
It plays pretty fast and the hits and loses are simply calculated with the included dice, making for a fun game that I still get pummelled at when playing my son.
There are even mercenaries and heavy soldiers I have yet to experiment with to add extra elements of battlefield realism to the game. I'm looking forward to discovering how they change the game.
I'm sure it's out of print (so many of the good games are), but you can no doubt find it out on the internet somewhere if you want it. I recommend you do so if you like war games from chess to Risk. It's lighter and quicker than those, but a good time and playable for even younger kids.