Disclosed is an aircraft braking system 100 comprising a plurality of brakes 25, 26, 35, 36, 25', 26', 35', 36' each for braking one of a plurality of aircraft wheels 23, 24, 33, 34 using hydraulic pressure, a first hydraulic pressure supply unit 310, and a second hydraulic pressure supply unit 320 , wherein the first hydraulic pressure supply unit is connected to only a first subset 25 of the plurality of brakes, such that the first hydraulic pressure supply unit can enable only the first subset of the plurality of brakes to provide braking, and wherein the second hydraulic pressure supply unit is connected to only a second subset 26 of the plurality of brakes, the second subset not including any of the brakes of the first subset, such that the second hydraulic pressure supply unit can enable only the second subset of the plurality of brakes to provide braking. Also disclosed is an aircraft landing gear 10, 20, 30 and a method of operating the aircraft braking system 100.