The Lanchester armoured car was born out of a requirement from the Royal Navy Air Service (R.N.A.S.) for a vehicle that could rescue pilots shot down behind enemy lines and provide some general armoured support on airfields. At the time Lanchester was a highly regarded British car manufacturer who, like their rivals Rolls Royce, would supply a chassis and engine after which the customer could have the body of their choice fitted by a separate coach-building company. This made them easily adaptable to the armoured car role.

The armoured car was based on the company's regular 38hp engined chassis, but with the addition of doubled-up rear tyres. The armoured body was built up on the chassis utilising 8mm plate for the front and sides, with thinner 4mm plate forming the roof and floor. A prototype was built in December 1914 and, after a number of modifications, went into production the following year. One of those modifications was the fitting of the small turret on top of the vehicle, armed with a Vickers .303 machine gun.



In total, 36 vehicles were produced and delivered to the RNAS on the western front. These were split into three squadrons of twelve vehicles each, with one squadron later serving as part of the Belgian Army. Later in 1915, all 36 vehicles were reassigned to the British Army, but given the war's deterioration into a trench-bound stalemate, the cars were returned to Britain. In December 1915, 22 Lanchesters were overhauled and supplied to the Imperial Russian Army. Some of the remaining vehicles were then deployed with the RNAS expeditionary force in the Caucasus and Romania with further detachments operating in Turkey and Persia.