Siege

From BoardGameGeek:

Siege is a two-player tactical level board-wargame, vaguely inspired by ancient Chess-like games such as Chinese Chess. Four knights (which move like Chess knights) attack a castle guarded by four footmen (like Kings) and a Commander (like Bishops but with a special Rook-like move). The terrain is divided into the Castle, lawn and moat (for lack of better terminology) and restricts the movement of pieces in various ways. Attacker wins by taking the Commander, defender wins by taking all attackers.