Battle of Imphal The Battle of Imphal took place in the region around the city of Imphal , the capital of the state of Manipur in North - East India from March until July 1944 . Japanese armies attempted to destroy the Allied forces at Imphal and invade India , but were driven back into Burma with heavy losses . Together with the simultaneous Battle of Kohima on the road by which the encircled Allied forces at Imphal were relieved , the battle was the turning point of the Burma Campaign , part of the South - East Asian Theatre of the Second World War . The defeat at Kohima and Imphal was the largest defeat to that date in Japanese history . The situation . At the start of 1944 , the war was going against the Japanese on several fronts . They were being driven back in the central and south west Pacific , and their merchant ships were under attack by Allied submarines and aircraft . In south east Asia , they had held their lines over the preceding year , but the Allies were preparing several offensives from India and the Chinese province of Yunnan into Burma . In particular , the town of Imphal in Manipur on the frontier with Burma was built up to be a substantial Allied logistic base , with airfields , encampments and supply dumps . Imphal was linked to an even larger base at Dimapur in the Brahmaputra River valley by a road which wound for through the steep and forested Naga Hills . Imphal was held by the IV Corps , commanded by Lieutenant - General Geoffrey Scoones . The corps was in turn part of the British Fourteenth Army under Lieutenant General William Slim . Because the Allies were planning to take the offensive themselves , the corps ' units were thrown forward almost to the Chindwin River and widely separated , and were therefore vulnerable to being isolated and surrounded . Japanese plan . In March 1943 , the Japanese command in Burma had been reorganised . A new headquarters , Burma Area Army , was created under Lieutenant - General Masakazu Kawabe . One of its subordinate formations , responsible for the central part of the front facing Imphal and Assam , was Fifteenth Army . Lieutenant - General Renya Mutaguchi was appointed to command this army in July 1943 . From the moment he took command , Mutaguchi forcefully advocated an invasion of India . His motives for doing so appear to be complex . He had played a major part in several Japanese victories , ever since the Marco Polo Bridge incident in 1937 , and believed it was his destiny to win the decisive battle of the war for Japan . He may also have been goaded by the first Chindit expedition , a raid behind Japanese lines launched by the British under Orde Wingate early in 1943 . The Allies had widely publicised the successful aspects of Wingate ' s expedition while concealing their losses to disease and exhaustion , possibly misleading Mutaguchi and some of his staff as to the difficulties they would later face . Mutaguchi planned to exploit the capture of Imphal by advancing to the Brahmaputra valley . This would cut the Allied lines of communication to the front in northern Burma , where the American - led Northern Combat Area Command was attempting to construct the Ledo Road to link India and China by land , and to the airfields supplying the Nationalist Chinese under Chiang Kai - shek via an airlift known as " The Hump " . Although the staffs at Burma Area Army and at Southern Expeditionary Army Group ( the supreme command for the Japanese forces in South East Asia and the southern Pacific ) had reservations over the scale of Mutaguchi ' s proposed operation , they were eventually won over by his persistent advocacy . Finally , Prime Minister Hideki Tojo and Imperial General Headquarters gave their approval to the plan . Mutaguchi intended to isolate and destroy the Allied units in their forward positions and then capture Imphal . His plan was named U - Go , or Operation C . In detail : At the insistence of Subhas Chandra Bose , leader of the Azad Hind ( a movement which sought to overthrow British rule in India by force , with Japanese assistance ) , the Indian National Army made a substantial contribution . ( Originally , the Japanese intended using them only for reconnaissance and propaganda . ) All Mutaguchi ' s divisional commanders disagreed with the plan to some extent . Sato distrusted Mutaguchi ' s motives , and Yanagita openly derided his abrasive superior as a " blockhead . " Yamauchi was already very ill and fatalistic . Their main reservations concerned supply . Mutaguchi had assumed that success would be achieved within three weeks , but adequate supplies after that period could be obtained only if the Japanese captured Allied supply dumps , as the torrential rains that the spring season would inevitably bring would make supply routes from the Chindwin impossible to traverse . Gambles such as Mutaguchi was making had worked in the past , but could no longer be relied upon , given nearly total Allied air superiority in the area and the improvement in morale and training of British and Indian troops . Mutaguchi proposed to use " Genghis Khan " rations , driving herds of buffalo and cattle rounded up throughout northern Burma across the Chindwin as meat rations on the hoof . Most of these unfortunate beasts died from lack of forage and rotted many miles from the troops they were intended to supply . There were other weaknesses in the plan which were to be revealed as the campaign progressed . The Japanese assumed that the British would be unable to use tanks on the steep jungle - covered hills around Imphal . For the sake of ease of movement and supply , the Japanese left behind most of their field artillery , their chief anti - tank weapon . As a result , the Japanese troops would have little protection against tanks . Based on his experiences in the campaigns in Malaya and Singapore and in the Japanese conquest of Burma in early 1942 , Mutaguchi dismissed British and Indian troops as inherently inferior . The troops he had met on those occasions had generally been inadequately trained and led . The Allies had by now largely overcome the administrative and organisational problems which had crippled their early efforts in Burma , and their troops were far better trained and motivated . Prelude to the operation . In late February , a local Japanese counter - attack was launched against Indian XV Corps in Arakan , using much the same tactics as Mutaguchi proposed to use . The attack failed when Allied aircraft parachuted supplies to cut - off troops , allowing them to stand firm , while the Japanese who had infiltrated behind them ran out of supplies . The engagement became known to the Allies as the Battle of the Admin Box . From this point onwards , the Allies were to place increasing faith and reliance on their transport aircraft . The planning of U - Go was too far advanced to take account of these developments . Even as the Japanese prepared to launch their attack , the Allies launched the airborne phase of the second Chindit expedition on 5 March 1944 . Japanese officers such as Major - General Noburo Tazoe , commanding the Japanese Army Air Force units in Burma , urged Mutaguchi to divert troops from his offensive to secure the Japanese rear areas against the Chindits . Mutaguchi dismissed these concerns , claiming that in a few weeks he would have occupied the air bases from which the Chindits were supplied . Opening phases of the battle . When they received intelligence that a major Japanese offensive was impending , Slim and Scoones planned to withdraw their forward divisions into the Imphal plain and force the Japanese to fight at the end of impossibly long and difficult lines of communication . However , they misjudged the date on which the Japanese were to attack , and the strength they would use against some objectives . The Japanese troops began to cross the Chindwin River on 8 March . Scoones gave his forward divisions orders to withdraw to Imphal only on 13 March . Tamu - Shenam . The 20th Indian Division under Major - General Douglas Gracey held Tamu near the Chindwin , and Moreh a short distance to the north , where a large supply dump had been established . On 20 March , there was a clash between six M3 Lee tanks of the 3rd Carabiniers and six Type 95 Ha - Go tanks leading Yamamoto ' s advance from the south . The lighter Japanese tanks were destroyed . Gracey was opposed to making any retreat , but on 25 March he was ordered to detach some of his division to provide a reserve for IV Corps . As this left the division too weak to hold Tamu and Moreh , they withdrew to the Shenam Saddle , a complex of hills through which the Imphal - Tamu road ran . The supply dump at Moreh was set ablaze , and 200 cattle there were slaughtered . The division fell back without difficulty , mainly because two of Yamamoto Force ' s battalions from the Japanese 15th Division ( II / 51 Regiment and III / 60 Regiment ) were delayed at Indaw in northern Burma by the Chindits and were unable to intervene . Tiddim - Bishenpur . Further south , 17th Indian Division under Major - General Cowan was cut off by the Japanese 33rd Division . Patrols from the division and from V Force ( an irregular force of locally - raised levies and guerrillas ) warned Cowan of a Japanese force advancing against the rear of the division as early as 8 March , allowing Cowan to regroup the division to protect its rear . On 13 March , the Japanese 215th Regiment attacked a supply dump at Milestone 109 , twenty miles behind Cowan ' s leading outposts , while the Japanese 214th Regiment seized Tongzang and a ridge named Tuitum Saddle across the road a few miles behind 17th Indian Division ' s main position . The Indian division began to withdraw on 14 March . At Tuitum Saddle , the Japanese 214th Regiment were unable to dig in properly before they were attacked by the 48th Indian Infantry Brigade on 15 March . The Japanese suffered heavy casualties and were forced away from the road . Further north , the Japanese captured the depot at Milestone 109 on 18 March , but Indian troops recovered it on 25 March . Cowan had taken steps to secure the most vulnerable point in the rear of his division , the bridge over the Manipur River . The division ' s rearguard crossed safely on 26 March , demolishing the bridge behind them . The division removed most of the vehicles , food and ammunition from the depot at Milestone 109 before resuming their retreat . Both the Japanese and the Indian division had suffered heavy casualties . Yanagita , the Japanese 33rd Division ' s commander , was already pessimistic , and was apparently unnerved by a garbled radio message which suggested that one of his regiments had been destroyed at Tongzang . He therefore did not press the pursuit against 17th Division , and advanced cautiously in spite of reprimands from Mutaguchi . Scoones had nevertheless been forced to send the bulk of his only reserve , 23rd Indian Infantry Division under Major - General Ouvry Lindfield Roberts , to the aid of 17th Division . The two divisions , supplied by parachute drops from Allied aircraft , made their way back to the Imphal plain , which they reached on 4 April . Sangshak - Litan . Meanwhile , Imphal had been left vulnerable to the Japanese 15th Division . The only force left covering the northern approaches to the base , Indian 50th Parachute Brigade , was roughly handled in the Battle of Sangshak by a regiment from the Japanese 31st Division on its way to Kohima . The Japanese 60th Regiment cut the main road a few miles north of Imphal on 28 March , while the 51st Regiment advanced on Imphal from the north - east , down the valley of the Iril River and a track from Litan , north - east of Imphal . However , the earlier diversionary attack launched by Japanese 55th Division in Arakan had already failed . Admiral Louis Mountbatten , the commander in chief of the Allied South East Asia Command , had taken steps to secure aircraft normally assigned to the " Hump " . Slim was able to use these to move the battle - hardened 5th Indian Infantry Division , including all its artillery and first - line transport ( jeep s and mules ) , by air from Arakan to the Central Front . The move was completed in only eleven days . Two of the division ' s three brigades went to Imphal , and their leading troops were in action north and east of Imphal on 3 April . Chin Hills . On the Japanese left flank , the INA ' s Subhas Brigade , led by Shah Nawaz Khan , reached the edge of the Chin Hills below Tiddim and Fort White at the end of March . From this position , the 2nd Battalion sent companies to relieve Japanese forces at Falam and to Hakha , from where in turn , Khan ' s forces sent out patrols and laid ambushes for the Chin guerrillas under the command of a British officer , taking a number of prisoners . In the middle of May , a force under Khan ' s Adjutant , Mahboob " Boobie " Ahmed , attacked and captured the hilltop fortress of Klang Klang . The 3rd Battalion meanwhile moved to Fort White - Tongzang area in premature anticipation of the destruction of Major General Frank Messervy ' s 7th Indian Infantry Division in the Arakan , which would allow it to receive volunteers . During the early part of the offensive , the " Bahadur Group " of the INA apparently achieved some success in inducing British Indian soldiers to desert . Stalemate . From the beginning of April , the Japanese attacked the Imphal plain from several directions : Bishenpur . The Japanese 33rd Division attacked from the south at Bishenpur , where they cut a secondary track from Silchar into the plain . A commando raid succeeded in destroying a suspension bridge , making the Silchar track unusable . The 17th and 23rd Indian Divisions were regrouping after their retreat , and Bishenpur was held only by 32nd Indian Infantry Brigade ( detached from 20th Division ) . The Japanese advanced through the hills to the west of Bishenpur , almost isolating the British in the village , but suffered severely from British artillery fire . Their leading troops were halted by lack of supply only from Imphal . Other Japanese advancing directly up the Tiddim - Imphal road were halted in villages south of Bishenpur , as troops of 17th Indian Division rejoined the battle . Yanagita , the Japanese division ' s commander , had already infuriated Mutaguchi by his caution . He was finally relieved of command at the end of the month . Shenam - Palel . " Yamamoto Force " attacked the Shenam Saddle , defended by the main body of the Indian 20th Division , on the main road from Tamu into Imphal . This was the only metalled road the Japanese could use , and it was vital for them to break through to allow Yamamoto ' s tanks and heavy artillery to attack the main defences around Imphal itself . Only a few miles north of the saddle was Palel airfield , one of the only two all - weather airfields in the plain , and vital to the defenders . A Japanese attack up the road on 4 April was disjointed ; the infantry were not ready to take part and twelve Japanese tanks were caught exposed on the road by British anti - tank guns . From 8 April to 22 April , there was heavy fighting for five peaks which commanded the road east of the Saddle . The Japanese captured a number of them , but Indian and British counter - attacks regained some of those initially lost . Casualties were heavy on both sides . Having failed to break through using the road , Yamamoto sent some troops through the rough terrain to the north of the Saddle to raid Palel airfield . The INA ' s Gandhi Brigade or 2nd Guerrilla Regiment , of two battalions led by Inayat Kiyani , took part in this attack . On 28 April , they attacked Palel . They tried to induce some Indian defenders to surrender , but the defenders rallied after initial hesitation . Another INA detachment carried out demolitions around Palel , but withdrew after they failed to rendezvous with Japanese units . The Gandhi Brigade was short of rations , having brought forward only one day ' s supplies , and also lost 250 casualties to shellfire after they pulled back from Palel . Kanglatongbi - Nungshigum . The Japanese 15th Division encircled Imphal from the north . Its 60th Regiment captured a British supply dump at Kanglatongbi on the main Imphal - Dimapur road a few miles north of Imphal , but the depot had been emptied of food and ammunition . A battalion of the Japanese 51st Regiment ( which was commanded by Colonel Kimio Omoto ) seized the vital Nungshigum Ridge , which overlooked the main airstrip at Imphal . This was a major threat to IV Corps and on 13 April the 5th Indian Division counter - attacked , supported by air strikes , massed artillery and the M3 Lee tanks of B Squadron of the 3rd Carabiniers . The Japanese had expected that the slopes were too steep for tanks to climb , and indeed Lee tanks had never been tried before on such gradients in action . The Japanese regiment had very few effective anti - tank weapons , and their troops were driven from the ridge with heavy casualties . The attackers also lost heavily ; every officer of the Carabiniers and the attacking infantry ( 1st Bn , the 17th Dogra Regiment ) was killed or wounded . Allied counter - attacks . North . By 1 May , all Japanese attacks had come to a halt . Slim and Scoones began a counter - offensive against the Japanese 15th Division . This division was the weakest of the Japanese formations , and if it was defeated , the siege would be broken ( once Kohima was recaptured ) . The progress of the counter - attack was slow . The monsoon had broken , making movement very difficult . Also , IV Corps was suffering some shortages . Although rations and reinforcements were delivered to Imphal by air , artillery ammunition had to be conserved . The 5th Indian Division ( joined by the 89th Indian Infantry Brigade which was flown in to replace the brigade sent to Kohima ) and 23rd Indian Division ( later replaced by the 20th Division ) tried capturing the steep ridges , such as the Mapao Spur , held by the Japanese , but found these to be almost impregnable . Allied artillery was usually unable to hit Japanese positions on the reverse slopes , and the troops often stormed the summits of the ridges , only to be driven off by mortar fire and grenades from the reverse slope positions . IV Corps regrouped . The 23rd Indian Division took over the defence of the Shenam Saddle , while from the end of the May , 5th Division concentrated on driving north from Sengmai up the main road through Kanglatongi , while the 20th Indian Division advanced along the tracks and the Iril River toward Litan and Ukhrul , threatening the Japanese 15th Division ' s lines of communication . By this time , the Japanese were at the end of their endurance . Neither the 31st Division which was fighting at Kohima nor the 15th Division had received adequate supplies since the offensive began , and their troops were starving . Lieutenant General Sato , the commander of the Japanese 31st Division , ordered a retreat at the end of May , so that his division could find food . This allowed Indian XXXIII Corps to drive the Japanese from Kohima , and advance south . The troops of Japanese 15th Division were forced to abandon their defensive positions to scavenge for supplies in local villages or on the Japanese lines of communication . Mutaguchi dismissed the mortally ill Yamauchi , but this did not change matters . After driving rearguards from the " Miyazaki Group " ( an independent detachment from the 31st Division ) and the Japanese 60th Regiment from their delaying positions on the Dimapur - Imphal road , the leading troops of IV Corps and XXXIII Corps met at Milestone 109 , north of Imphal , on 22 June , and the siege of Imphal was raised . South . South of Imphal , 17th Indian Division had moved back into the line , facing the Japanese 33rd Division . During the first half of May , there were several Japanese air attacks on Bishenpur , and heavy fighting for the village of Potsangbam to the south , in which the British lost 12 tanks . The surviving crews of the 3rd Carabineers were later flown out of Imphal to be reconstituted in India . Major General Cowan planned to break the deadlock on this front by sending the 48th Indian Infantry Brigade on a wide left hook into the Japanese division ' s rear while 63rd Indian Infantry Brigade attacked them in front . The Japanese division ' s temporary commander ( its Chief of Staff , Major General Tetsujiro Tanaka ) planned at the same time to infiltrate through Indian 17th Division ' s front to seize vital objectives in the middle of the Indian positions . Both moves were launched almost simultaneously . The Gurkhas of 48th Indian Brigade cut the road behind the Japanese on 18 May , but 63rd Indian Brigade were unable to break through to them , and 48th Brigade was forced to fight its way through the Japanese positions to rejoin the division , with heavy losses . Meanwhile , some of Tanaka ' s troops ( the 214th Regiment ) captured hills close to 17th Division ' s headquarters on 20 May . Because of the incursion into their own rear , the Japanese were unable to reinforce their forward troops , and over the following week the isolated Japanese were driven from their positions in the middle of the Indian division , many parties being wiped out . A new forceful commander , Lieutenant General Nobuo Tanaka , took command of the 33rd Division on 22 May , and ordered repeated attacks which reduced many of his division ' s battalions to mere handfuls of men . In June , he received reinforcements ( a regiment from the Japanese 53rd Division , and a detachment from the 14th Tank Regiment ) and used them to launch another attack . After initial success , the fresh regiment suffered heavy casualties from shellfire . By the end of June , the 33rd Division had suffered so many casualties that they could make no further effort . Yamamoto Force had also suffered heavy casualties , but before withdrawing , they launched two successful raids on Palel Airfield in the first week of July , destroying several parked aircraft . INA operations . Towards the end of May , the INA ' s 1st Guerrilla Regiment had been redirected to Kohima . Shah Nahwaz Khan moved north across the Japanese rear but by the time he reached Ukhrul , the Japanese had already begun to withdraw . Khan decided to attack Imphal instead . At Imphal , his unit suffered some desertions , but not on the scale that the Commonwealth forces expected . End of the battle . The Japanese had realised that the operation ought to be broken off as early as May . Lieutenant General Hikosaburo Hata , the Vice - Chief of the General Staff , had made a tour of inspection of Southern Army ' s headquarters in late April . When he returned to Tokyo , he reported pessimistically on the outcome of the operation at a large staff meeting to Prime Minister Hideki Tojo , but Tojo dismissed his concerns as their source was a junior staff officer ( Major Masaru Ushiro , at Burma Area Army HQ ) . Messages were sent from Imperial Headquarters , urging that the operation was to be fought to the end . Lieutenant General Kawabe had travelled north to see the situation for himself on 25 May . Several officers whom he interviewed expressed confidence in success if reinforcements could be provided , but actually concealed their losses and the seriousness of the situation . At a meeting between Mutaguchi and Kawabe on 6 June , both used " haragei " , an unspoken form of communication using gesture , expression and tone of voice , to convey their conviction that success was impossible , but neither of them wished to bear the responsibility of ordering a retreat . Kawabe subsequently became ill with dysentery and perhaps physically unfit for duty . He nevertheless ordered repeated attacks , stating later that Bose was the key to Japan ' s and India ' s future . Mutaguchi ordered the Japanese 31st Division , which had retreated from Kohima when threatened with starvation , to join the 15th Division in a renewed attack on Imphal from the north . Neither division obeyed the order , being in no condition to comply . When he realised that none of his formations were obeying his orders to attack , Mutaguchi finally ordered the offensive to be broken off on 3 July . The Japanese , reduced in many cases to a rabble , fell back to the Chindwin , abandoning their artillery , transport , and many soldiers too badly wounded or sick to walk . The defeat at Kohima and Imphal was the largest defeat to that date in Japanese history . They had suffered 55 , 000 casualties , including 13 , 500 dead . Most of these losses were the result of starvation , disease and exhaustion . ( The Allies suffered 17 , 500 casualties , almost entirely from battle . ) The Japanese had also lost almost every one of the 12 , 000 pack horses and mules in their transport units and the 30 , 000 cattle used either as beasts of burden or as rations . The loss of pack animals was to cripple several of their divisions during the following year . Mutaguchi had sacked all of his divisions ' commanders during the battle . Both he and Kawabe were themselves subsequently relieved of command . In December , Slim and three of his corps commanders ( Scoones , Christison and Stopford ) were knighted by the viceroy Lord Wavell , at a ceremony at Imphal in front of Scottish , Gurkha and Punjab regiments . Slim was created KCB , the others were made KBE s . Air operations at Imphal . By mid - 1944 , the Allied air forces enjoyed undisputed air supremacy over Burma . The last major effort by the Japanese Army Air Force had been over the Arakan in February and March , when they had suffered severe losses . During the Imphal and Kohima battles , they were able to make barely half a dozen significant raids . IV Corps enjoyed close air support from fighter - bombers and dive bombers of 221 Group of the RAF . Allied fighter bombers and medium bombers shot up and bombed enemy concentrations , supply dumps , transport , roads and bridges all the way to the Chindwin river . The monsoon in no way diminished their activity . The RAF Third Tactical Air Force increased their sortie rate to 24 , 000 sorties during the worst four months of the monsoon , nearly six times the figure of the previous year ’ s record . However , the most important contribution to the Allied victory was made by both British and American transport aircraft . The Allies could fly men , equipment and supplies into the airstrips at Imphal ( and Palel also , until the onset of the monsoon rains ) , so although cut off by land , the town was not without a lifeline . By the end of the battle the Allied air forces had flown 19 , 000 tons of supplies and 12 , 000 men into Kohima and Imphal , and flown out 13 , 000 casualties and 43 , 000 non - combatants . Among the supplies carried during the siege were over a millon gallons of fuel , over a thousand bags of mail and 40 million cigarettes . Several thousand mules , many shipped from Missouri , were used to supply outlying outposts , for example 17th Indian Division up the Bishenpur trail , so animal fodder was also flown in during the siege . Allied aircraft could also parachute ammunition , rations and even drinking water to surrounded units . At the start of the battle , South East Asia Command had 76 transport aircraft ( mainly C - 47 Skytrain ) available , but many others were dedicated to supplying the Nationalist Chinese under Chiang Kai - Shek , or to establishing USAAF bomber bases in China , via " the hump " . Not even Admiral Louis Mountbatten , the Commander - in - Chief , had the authority to commandeer any of these aircraft , but at the crisis of the battle in the middle of March he nevertheless did so , acquiring 20 C - 46 Commando aircraft ( equivalent to another 30 C - 47s ) . He was supported by American officers at SEAC and the American China - Burma - India Theater headquarters . War cemetery . After the war , the Commonwealth War Graves Commission set up cemeteries in Imphal and Kohima to commemorate the British and the Indian soldiers who died during the Second World War .