The A10 was also known as the Cruiser Mk II and was developed alonside the A9. The A10 was crewed by 5 men armed with a 2 pounder and introduced in December 1939. A number of A10 were converted to A10 CS (Close Support) by fitting a 3.7" (94mm) howitzer in place of the 2 pounder which allowed an ammo load of smoke and high explosive shells. A10 served with the BEF in France and later in 1941 in the defence of Tobruk in North Africa.