Fearing attack from both Chinese and Indian forces, the Japanese Fifteenth Army launched an attack on British forces collectin in India during the spring of 1944. The attack, mounted from Burma, was intended as a preemptive strike to knock out British forces led by General William Slim before they gathered enough strength to over-run Japan's weak and isolated troops stationed in Burma. Their plan was to take the communication stations of Kohima and Imphal, held by British and Indian forces, before advancing on Bengal. Slim planned to launch his attack from the plain of Imphal, a large area of open ground, the only terrain in the area suitable for airfields. Slims communication line ran from his base north for two hundred and ten kilometers through the pass at Kohima to the start of the Assam railway system in Dimapur. Despite the fact that the communication line ran parallel with the front line for just under one hundred and thirty kilometers, Slim was not daunted, as it was thought to be impossible that any Japanese force bigger than a battalion would be able to penetrate the sixty five kilometer stretch of jungle growing between the Japanese based on the Chindwin river and the road. Consequently, it was considered unnecessary to have a force any bigger than a battalion to control the eastern approach to Kohima.
Simultaneous with outbreaks of fighting around Imphal, Japanese troops began to push through dense jungle toward Kohima. Fearing attacks on their communication lines, the British sent Colonel Hugh Richards to Kohima to oversee the defenses. A veteran of the First World War, Richards had led the 3rd West African Brigade as part of the Chindit special forces, before being relieved of his command after the revelation that, at fifty years of age, he was ten years to old to serve with his unit. Arriving March 23rd, Richards learned that under his command would be the Assam Regiment Battalion, a Native State battalion and a number of poorly trained soldiers, some of whom had had no actual training in the handling of weapons. Staking out his defensive position at Kohima Ridge, Richards learned on the twenty-seventh of March that the entire Japanese 31st Division was advancing upon him, led by Lieutenant-General Sato. On April 5th, reinforcements arrived to support Richards, the majority of the Native State battalion having fled. Richards now had under his command members of the 4th Battalion Royal West Kent Regiment, part of the 161st Brigade, along with the 20th Mountain Battery and the Indian Artillery, totaling in 1,500 combat-capable men. However, Sato had by now moved more than 15,000 men through the treacherous Assam terrain, but also brought in 75 mm guns, deployed to pound the ridge. Daily, new troops were being drafted in to join the onslaught, and slowly Richards' perimeter began to shrink. At one section of the ridge, the two opposing forces were separated from each other only by the width of a tenniscourt which lay behind the commissioners bungalow, occupied by the Japanese. In order to retake it, the British drove a tank up to the front door and discharged a number of shells inside.
One of the many outstanding feats of Kohima was the remarkable accuracy with which the remaining guns of 161st Brigade were fired. Officers from the 20th Mountain Battery ordered the guns to be fired at a hill 2.3 km from Kohima, where the brigade had been brought to a halt by the Japanese whilst en route to assist Richards. It was said that the guns were fired so accurately that at one point a curtain of defensive fire was laid only 13.5 m away from the garrisons forward positions.
One of the key weapons used in the defense of Kohima was the Bren light machine-gun, a British .303 version of a Czechoslovakian weapon, featuring a curved 28 round magazine. Brought into service in 1938, every section of a platoon in a rifle company was equipped with a two-man Bren group, comprising of one man to operate the gun, and another to reload it and change the barrel before it overheated. Each gun was supplied with two air-cooled barrels and 25 magazines. The gun could fire accurately up to 1,829 meters and could fire at a rate of 500 rounds per minute.
On April 13th, nicknamed "The Black 13th", a supply parachute drop failed when most of the mortar ammunition and the much needed drinking water fell behind Japanese lines. The enemy guns then opened up on the hospital trenches, packed with the wounded, as Sato's infantry attack continued. Knowing they only had to resist for four more days, Richards' men fought on vigorously, until April 18th, when forces arrived to relieve Richards and his men, who were by now clustered into a box measures no more than 320 m square, after suffering in total more than 600 casualties.
The Battle of Kohima raged on after Richards' men had been relieved. Sato ordered a number of his men to construct a fortified line in the pass, which they defended ferociously. Slim placed enormous pressure on Sato in order to re-open the pass, which continued even after the breaking of the monsoon at the end of May. Slowly the Japanese gave ground, until on the 22nd of June the Japanese fortified line broke, and the pass was once again re-opened, forcing the Fifteenth Army into retreat.
After the battle, Lieutenant-General Kotoku Sato became unnerved and disobeyed a direct order to join his men up with other Japanese forces for a last-ditch attempt to defeat the British further south, and was consequently dismissed. On the battlefield, the tree's once thick with foliage lay bare, and the buildings had for the most part been reduced to ruble.
Subsequent to the advance of the Japanese army, Britain was able to re-take Burma, after the Japanese army became severely weakened with casualties (65,000 dead), starvation and a lack of ammunition, though continued to fight, despite coming under attack from both land and air. It was the Battle of Kohima, the battle of which the Burma campaign centered around, which eventually turned the tide in favour of the British in the struggle for Southeast Asia.
Great Battlefields of the World, by John MacDonald