Developed in 1938 through 1941 on the basis of the M2. Mass-produced from 1941. More than 13,000 vehicles in various versions were built, from the M3 to the M3A3, all of which were supplied to almost every allied nation under Lend-Lease. The M3 tanks were designated Stuart I by the British, while the M3A1 version received the designation Stuart III. The M3 first saw action in the battle at Sidi Rezegh.