The AEC Militant (or "Milly") was a post-war development by AEC of the AEC Matador artillery tractor used during World War II. Externally the most noticeable development was that the Mark 1 Militants had six wheels compared to the Matador's 4. Other changes included the fitting of a larger, 11.3-litre 6-cylinder diesel engine and the use of a steel frame for the cab, rather than the ash (fraxinus) wood frame of the Matador. The Militant Mark 1 was produced in both 6x4 (6 wheels, 4 driven) and 6x6 form (6 wheels, 6 driven).
Although primarily intended as a replacement for the Matador artillery tractor, other variants included an articulated lorry tractor unit, a General Service or cargo lorry with a longer wheelbase and as a chassis for mounting various cranes, usually supplied by Coles.
The Militant served with the British Army and some other armies in most parts of the world. It was intended as an improved artillery tractor, but following the Second World War, the development of large artillery pieces was gradually dropped in favour of more effective rockets and missiles, making this role largely redundant during the Militant's service life. Crews had mixed views of the Militant. Because it had no power steering, it took considerable effort to turn the wheel at slow speeds and in difficult conditions. However it was credited with a good cross-country performance and was often used to recover the six-wheel drive Alvis Stalwart amphibious lorries that bogged in difficult conditions.
AEC MkI did not have power steering but the MkIII had a power assist Steering Ram.
Most variants were fitted with a chassis mounted winch that was driven through the gearbox. This winch, which was intended for maneuvering of the towed field gun and for self-recovery of the vehicle; it proved extremely strong and reliable. The Militant gained the nickname 'Knocker' from its military crews which may have been due to the rhythmic sound of the slow-revving engines.
The Knocker was the nickname of the MkI and the one MkI CALM was still in service with each RCT Transport Squadron until the AEC Fleet was replaced by the Bedford 14 Tonne 6X6 in the early 90s. AEC MkIII Recovery Trucks were replaced by Foden GS Recovery 6X6.
Many Militants were sold off by the Army in the 1970s and were purchased as heavy recovery vehicles or for forestry use by civilian operators. They were not as popular for forestry operations as their predecessor the Matador because the extra length and an extra axle made them less maneuverable in confined spaces. However, some users simply shortened the chassis and removed one axle, effectively creating a more powerful version of the Matador.