The next third-generation MkIII of 7,5-ton model Monarch was presented in 1947. It can be distinguished by the bottom of the cabs, specific for postwar AEC trucks. The trucks were equipped with the 7.7 liter AEC diesel engines with output of 95 hp. The new generation has pneumatic brakes. The novelties for this version were 5-speed gearbox and roller bearings in the drive of rear wheels.