The relief of Kohima

By the end of April 1944 Kohima in Assam was no longer under siege. The garrison, which since 6 April had been holding out on a few hills of the ridge against Lieutenant General Kōtoku Satō’s Japanese 31st Division, had been relieved, and the road from Dimapur to Kohima was in British hands again. But the battle went on: the Japanese still held most of the ridge, and further south their roadblocks closed the road to Imphal, where IV Corps had been fighting in encirclement since the end of March.

Under 24 April it is often stated that “British troops force open the road from Imphal to Kohima”. That is not what happened. The breakthrough at Kohima came earlier – on 18 April, when units advancing from Dimapur broke through to the defenders. The road from Kohima to Imphal, on the other hand, remained closed for another two months: it was reopened only on 22 June, when troops advancing from Kohima met troops from Imphal at Milestone 109. Around 24 April the British 2nd Division was taking over the whole Kohima sector and preparing an attack to push the Japanese off the ridge.

The breakthrough from Dimapur

Major General John Grover’s British 2nd Division began arriving by rail at Dimapur at the beginning of April. It was a division trained for amphibious landings, not for fighting in jungle and mountains, and it came from the interior of India piecemeal, battalion by battalion. Even so, according to the British official history, by about 11 April Lieutenant General Montagu Stopford’s XXXIII Corps had roughly as many troops in the area as the Japanese, and its superiority in artillery, tanks and aircraft grew by the day.

Between Dimapur and Kohima the Japanese had set up roadblocks, the strongest near the village of Zubza. The British 5th Brigade broke through them in heavy fighting and on 15 April linked up with the Indian 161st Brigade, which had been cut off since 5 April in its box at Jotsoma, a few kilometres from the Kohima ridge. The British 6th Brigade took over the positions at Jotsoma, and the 161st Brigade was free to go to the aid of its own battalion holding out in Kohima.

On the morning of 18 April, after a heavy artillery bombardment and with the support of tanks of the 149th Regiment, Royal Armoured Corps, and of aircraft, the brigade’s leading units – the 1st Battalion, 1st Punjab Regiment – broke through to Garrison Hill. They arrived at the last moment. On the night of 17–18 April the Japanese had taken the Deputy Commissioner’s bungalow and Kuki Picquet, splitting the defence in two. The defenders now held only part of Garrison Hill, but the exhausted and hungry Japanese were unable to finish them off.

The garrison relieved

Fully securing the road from Jotsoma to the ridge took another day. On the night of 18–19 April some 300 wounded were carried out and driven away under fire. On 19 April and during the night of 19–20 April battalions of the British 6th Brigade moved onto Garrison Hill, and at six in the morning on 20 April Colonel Hugh Richards handed over command of the sector to them. Officers of the 6th Brigade later described the shock of seeing the defenders: filthy, unshaven, emaciated men who had barely slept for two weeks, amid craters, shattered trees, unburied bodies and the stench of decay. The ridge looked like a battlefield of the First World War.

Lieutenant Colonel John Laverty’s battalion of the Royal West Kents, the core of the defence, lost about 200 killed and wounded according to British figures – roughly a third of its strength. The losses of the garrison as a whole are given variously, usually as several hundred men. In Britain and India the siege became a legend – it was later called “the British Thermopylae”, and the whole battle together with Imphal “the Stalingrad of the East” – but for the battle itself the relief of the garrison was only the beginning.

The fight for the ridge at the end of April

Satō had no intention of giving way. His battalions, including Major General Shigesaburō Miyazaki’s 58th Regiment, held the bungalow and Kuki Picquet, FSD, DIS and Jail Hill, GPT Ridge to the south and the Naga village to the north. The Japanese bunkers were dug deep into the slopes, covered one another and survived even heavy artillery fire. After the garrison was relieved, Miyazaki tried for several more nights to take Garrison Hill. On Kuki Picquet the trenches were less than 50 metres from the British positions, and the fighting often turned hand-to-hand. On the night of 26–27 April the British retook the club building above the Deputy Commissioner’s bungalow, from which the centre of the Japanese positions could be observed.

Grover and Stopford decided not to assault the ridge only from the front. At the end of April the 4th Brigade set off on a wide outflanking march from the south, across the wooded slopes of the Pulebadze massif, to strike at GPT Ridge, while the 5th Brigade moved from the north towards the Naga village. Meanwhile the monsoon was setting in. The steep slopes turned to mud; in places the men of the 4th Brigade cut steps into them and built handrails, and all supplies were carried by porters and mules. The outflanking moves went much more slowly than planned.

Satō had troubles of his own. His division was receiving from the rear only a fraction of the food and ammunition it needed, and British aircraft ruled the skies. In April Fifteenth Army headquarters sent him contradictory orders: Lieutenant General Renya Mutaguchi, whose attack on Imphal had stalled, wanted the 31st Division, or part of it, to come to his aid at Imphal, although it was barely holding its positions at Kohima. Satō was increasingly open in his view that army headquarters did not understand his situation.

Imphal still surrounded

While the fight for the ridge went on at Kohima, Lieutenant General Geoffry Scoones’s IV Corps was defending Imphal against attacks from four directions. On 13 April the Indian 5th Division retook the Nungshigum ridge, from which Japanese troops of the 51st Regiment had been threatening the main airfield. M3 Lee tanks of the 3rd Carabiniers climbed slopes the Japanese had thought impassable for vehicles; every officer of the squadron and of the attacking Indian infantry battalion was killed or wounded. In the east, above the Shenam Pass, fighting raged from 8 to 22 April for five peaks dominating the road from Tamu. In the south, Lieutenant General Genzō Yanagida’s 33rd Division approached Bishenpur and cut the mountain track to Silchar.

From 18 April Imphal was supplied by air under Operation Stamina. RAF and USAAF transport aircraft flew in food, ammunition and fuel and flew out the wounded and surplus service troops. Even so, the rations in Imphal had to be cut, and the artillery was beginning to run short of ammunition. On 28 April the airfield at Palel was attacked by a regiment of the Indian National Army – the so-called Gandhi Brigade – raised by Subhas Chandra Bose from prisoners of war and Indians living in South-East Asia. The attack was beaten off. By the end of April the Japanese offensive at Imphal was clearly losing momentum; according to British studies, by 1 May all the Japanese attacks on the plain had been halted.

In Tokyo and in the headquarters in South-East Asia it was beginning to be recognised that Operation U-Go was going badly. At the end of April the Deputy Chief of the General Staff, Lieutenant General Hikosaburō Hata, toured the headquarters in the south and on his return presented a pessimistic report to Prime Minister Hideki Tōjō. Tōjō brushed it aside, and Imperial General Headquarters ordered the fighting to continue.

Place in the war

The relief of 18 April settled that the Japanese would neither take Kohima nor march on Dimapur. From then on the initiative at Kohima gradually passed to the British. On 4 May the 2nd Division and the Indian 7th Division, brought in from the Arakan, launched an attack on the whole ridge. On 13 May, after sappers had levelled a track up to the higher terrace, a tank drove down onto the former tennis court and destroyed the Japanese bunkers by the bungalow; the Kohima ridge was cleared. At the turn of May and June Satō, whose men were starving, began to withdraw his division against Mutaguchi’s orders – one of the few cases in the history of the Japanese army of a divisional commander withdrawing from the battlefield on his own authority. Mutaguchi relieved him of his command.

The road from Kohima to Imphal, whose reopening is sometimes dated to 24 April, was reopened on 22 June. That day the spearheads of the British 2nd Division, advancing south from Kohima, met units of IV Corps’ Indian 5th Division at Milestone 109, some 16 kilometres north of Imphal. The siege of Imphal was over. At the beginning of July Mutaguchi called off the operation, and the retreat of the shattered Fifteenth Army across the mountains in the monsoon, amid hunger and disease, completed the heaviest defeat the Japanese army had suffered on land up to that time. For Lieutenant General William Slim’s Fourteenth Army it was the turning point of the war in Burma: in the months that followed, it was the Fourteenth Army that went over to the offensive.