Cavalry Charger( Complete Warrior, p. 108)
[Fighter Bonus Feat, Tactical]
Fighting from the back of a steed is second nature to you.
The Cavalry Charger feat enables the use of three tactical maneuvers. Unhorse: To use this maneuver, you must be mounted and charge a mounted foe. If your charge attack hits, you may make a free bull rush attempt. If the bull rush attempt succeeds, you move your foe normally, but his mount remains where it was. Leaping Charge: To use this maneuver, you must be mounted and charge a foe at least one size category smaller than your mount. Make a Ride check at the conclusion of the move portion of the charge action. Prior to making the roll, determine the DC of the check: either DC 10 for a chance to deal 2 extra points of damage or DC 20 for a chance to deal 4 extra points of damage. If you fail this Ride check, you miss your target (no attack roll) and if you fail this Ride check by 5 or more, you miss your target and fall off your mount, landing in a square adjacent to the mount's space. Fell Trample: You can make mounted overrun attempts against more than one foe, resolving each attempt according to the rules on page 157 and 158 of the Player's Handbook. Your mount gets a hoof attack against each foe you successfully overrun.
A fighter may select Cavalry Charger as one of his fighter bonus feats.