The Battles of Imphal and Kohima were a crucial turning point in the attempted Japanese invasion of India during World War Two. By October 1942 Singapore, Hong-Kong, Malaysia and Burma had all fallen to the Japanese; the Imperial army looked unbeatable. Yet it was then, when morale was at its lowest, that the new British commander Bill Slim set about reforming and rebuilding the Anglo-Indian British army. Slim aimed to revive Allied fortunes in the region – something many believed was an impossible task. Meanwhile, Japanese commander Renya Mutaguchi had ambitious plans of his own: the conquest of British India.

To initiate this plan the Japanese first had to capture one key strategic town: Imphal, the gateway to India. The very close-run battles that followed - fought between March and July 1944 - were clashes on epic proportions as each side attempted to execute a master plan of their respective visionary generals. If they succeeded, Slim knew the British would have a strong base from where they could commence their reconquest of Burma and quell the rise of Japan. If they failed, then the gates to all British India would be open to the Japanese army. The eventual, hard-fought Anglo-Indian victory proved the turning point in the Burma campaign and paved the way for the British-led reconquest of Burma and the eventual Allied victory in south-east Asia.

In this exclusive documentary, renowned World War Two historian James Holland sets himself the challenge of discovering the truth about the Battles of Imphal and Kohima. Accompanied by leading historians, James visits the various well-preserved battlefields – one of the first western historians to do so since the end of the Second World War – to reveal the viciousness of the fighting, the lingering logistical problems both sides faced and the tactical skill and barefaced courage of those who fought in one of the most decisive battles of World War Two. This is the truly epic tale of Britain’s greatest battle.