In the Burma Campaign, the M3 medium tank's main task was infantry support. It played a pivotal role during the Battle of Imphal, during which the Imperial Japanese Army's 14th Tank Regiment (primarily equipped with their own Type 95 Ha-Go light tanks, together with a handful of captured British M3 Stuart light tanks as well) encountered M3 medium tanks for the first time and found their light tanks outgunned and outmatched by the better British armour. Despite their worse-than-average off-road performance, the British M3 tanks performed well as they traversed the steep hillsides around Imphal and defeated the assaulting Japanese forces. Officially declared obsolete in April 1944, nevertheless, the Lee/Grant saw action until the end of the war in September 1945.