7th March 1944
The Japanese offensive 'U-GO' begins. The aim is to destroy all British forces around Imphal and Kohima, and then to push on through the passes to Dimapur, cutting off the Chinese and Americans in the north, and with the road to India ahead. Three divisions of General Mutaguchi's 15th Army are to be employed in the initial operations. The offensive begins with General Yamagid's 33rd Division against the positions of General Cowan's 17th Indian Division around Tiddim. These attacks are meant to commit the British reserves so that when the main attack goes in, its task will be easier. The British are well aware that the Japanese plan to attack, but they underestimate the strength of the force to be used. The plan is for the 17th and 20th Indian Divisions, both in fairly advanced positions, to fall back around Imphal and protect and live off, the large base organisations there. The British forces at this stage are all from General Scoones’ IV Corps. It is an essential part of the Japanese plan to capture large quantities of British supplies because most of their advances are to be made over jungle tracks which are impassable to supply vehicles. Food is the crucial element of the problem. It is precisely because of these difficulties that the British expect a smaller attack.
9th March 1944
News of the advance of the 33rd Division reaches General Cowan's headquarters but it is not at first believed.
10th March 1944
The Japanese 33rd Division as well as attacking the 17th Division, is infiltrating behind 20th Division, but their advances in this sector are held near Witok. More Chindit forces are flying to central Burma and are already disrupting Japanese communications with the forces facing Stilwell's Chinese and the American troops. In the Arakan, Buthidaung falls to the British.
13th March 1944
General Scoones authorises the 17th and 20th Divisions to withdraw from their advanced positions to Imphal. General Gracey with 20th Division has made better preparations for this move to Imphal, than Cowan with the 17th. Scoones and his superiors, Slim and Gifford, agree that reinforcements are needed and Mountbatten therefore sends requests to the highest level, for the use of American aircraft (those normally used for ferrying supplies to the Chinese) to move the 5th Division from the Arakan. The Japanese begin air attacks against the Chindit's 'Broadway' airfield.
15th March 1944
The main effort of the Japanese offensive begins with crossings over the Chindwin by the 15th and 31st Divisions, in several places north of Homalin.
17th March 1944
There are heavy Japanese air attacks on the Chindit's landing ground at 'Broadway'. Several of the supporting spitfires are destroyed on the ground.
20th March 1944
The 1st Brigade of the 5th Division arrives at Imphal by air. A battalion is sent to Kohima.
24th March 1944
General Wingate is killed in an air crash. The senior Chindit, Brigadier Commander Lentaigne replaces him.
27th March 1944
General Stopford's 33 Corps is put under Slim's control and ordered to concentrate at Dimapur before advancing to Kohima. A second Brigade of the 5th Division arrives at Imphal by air and the third brigade is being sent to Dimapur also for Kohima.
29th March 1944
The roads between Imphal and Kohima are cut by Sato's 31st Division at Maram. Slim sticks to his plan to supply the garrison at Imphal by air.
2nd April 1944
Mutaguchi's troops continue their advance. They now cut the road between Kohima and Imphal. South of Imphal, the 17th Indian Division has nearly completed its retirement to the main position.
4th April 1944
The Japanese 31st Division begins to put real pressure on the British positions at Kohima, cutting both routes out of the town at the rear. It is vital for the Japanese to capture this British supply centre as they are relying on its resources for their own replenishment.
7th April 1944
Near Kohima, the Japanese encircle the 161st Brigade from Stopford's 33 Corps at Jutsoma, and block the main road to the west near Zubza.
10th April 1944
Slim now feels that he has the complete picture of the situation and that an offensive is practical and necessary. The troops surrounded at Imphal and Kohima are to continue to be supplied by air and particularly in the case of the Imphal garrison, are to break through and relieve Kohima.
14th April 1944
The Japanese road block at Zubza is broken and the 161st Brigade at Jotsoma is relieved by the attacks of other units of the 2nd Indian Division.
30th April 1944
In the continuing battle for Imphal, the Japanese attacks are being gradually worn down, especially as their food shortage becomes serious. The defence of the 20th Division on the Shenam Ridge is particularly stout. The battle goes on.
17th May 1944
Merrill's Marauders help the Chinese forces to capture Myitkyina airfield.
24th May 1944
There are strong counter attacks by units of the Japanese 18th Army, south of Myitkyina.
2nd June 1944
The final siege of Myitkyina begins.
5th June 1944
At Kohima, an outflanking attack at last forces the Japanese off the Aradura Spur and into retreat. It still remains to clear the road to Imphal.
6th June 1944
'D' Day in Europe
22nd June 1944
The siege of Imphal is raised when advance units of the 2nd British Division link with the 5th Indian Division at Milestone 107 on the Imphal to Kohima road. The Japanese are taking ever heavier losses both in combat and, more seriously, because of food shortages and illness, as their supply system collapses.
3rd August 1944
Myitkyina is finally taken by the Chinese and American attack after the bulk of the Japanese garrison have managed to slip away.
4th August 1944
The British 2nd Division from 33 Corps takes Tamu.
4th November 1944
In the 14th Army's advance, the 5th Indian Division takes 'Kennedy Peak' south of Tiddim.
5th November 1944
Fort White, just south of Tiddim, is taken by the British advance.
12th December 1944
A British offensive begins in the Arakan; the attacking unit is 15 Corps and the objective is Akyab. Three divisions are in on the attack.