You've never heard of the Total War series? What kind of geek website is this (no offense)? The Total War series are the creators most accurate and strategic war games. They were so accurate they've been used many times by the History channel and educational programs to show how certain battles went. Medeival Total War was one of the oldest Total War games but, in my opinion, one of the best. During many battles, I was heavily outnumbered (one was 3000 to 420) and these battles could be easily won if you incorporated the right tactics. For example, you can defeat hundreds of enemy soldiers easily just by attacking a flank. Also, the game was realistic because they included the fear factor. If a certain type of soldier was outnumbered he might run away. But other soldiers who were taken from their parents and trained from childhood will fight to the death. The infos about these soldier types are included in the "information page" which are also accurate.
This game is sold for 10 to 20 dollars so it's a bargain and works on very old computers.