Following the loss of Malaya and Singapore it was obvious that Burma would be the next Japanese target, Lt-General T.J. Hutton was sent to take command, tasked with defending Burma, Particularly Rangoon and preparing for offensive operations against Siam. Hutton established northern supply depots once he realised how vulnerable Rangoon was.
Lt. General Hutton had only two divisions for the defence of Burma, the 17th Indian and 1st Burma. When the Japanese invaded Burma with elements of the Japanese Southern Army moving first, crossing the Kra Isthmus from Chumpon with a single battalion encountering no opposition and occupied Victoria Point and its important airfield on 16th December. Other battalions then drove north along the coast road, through Tenasserim to Tavoy which they reached on 9th January, isolating Mergui and its airfield.
The next day, the Japanese 55th Division left Raheng in Thailand and drove west over the Burmese border to meet the Southern Army at Moulmein, having thoroughly routed the British 16th Brigade at Kawkareik, the survivors staggering back towards Moulmein. The Japanese arrived at Moulmein on 30th January and the next day were already threatening Martaban and the road to Sittang, and Rangoon, both of which were already suffering from heavy Japanese air raids.
Major-General Smyth, VC knew he had to get his 17th British Division and its exhausted and inexperienced units first to the Bilin River and then to Sittang Bridge otherwise they would be trapped. His first requests to do so were refused by the inexperienced command staff and his troops had to fight desperately on the Bilin river and suffered heavy losses, only then to withdraw 20 miles along a dusty track under pressure from two Japanese who were provided with excellent air cover.
On the morning of 21st February, the 33rd Japanese Division had been kept at bay by the rearguard, but other Japanese forces had outflanked the British in the race to Sittang bridge. By evening, Smyth's HQ reached the bridge, set up defence posts and the transport of the division streamed across while three battalions of Gurkhas' fought off ferocious attacks by Japanese forces closing in from all sides.
Intelligence reports then warned of a possible parachute attack from behind, the main Gurkha force was cut off and Smyth was forced to leave them behind and blow the bridge. The bridge was blown at 0530 on the morning of 23rd February.
Thankfully, the Japanese immediately switched their attention to finding another crossing and the fit survivors of the rearguard swam the river but had to leave behind all their equipment and wounded, who were all butchered as soon as they were found by the Japanese.
General Smyth's Division now suffered yet another command foul-up, being ordered to leave the only good defensive position they had occupied behind the Sittang river. The 17th Division was now down to less than half strength and had lost the bulk of its guns and transport, but the survivors reached Pegu where they were reinforced by 7th Armoured Brigade (7th Hussars and 2nd Royal Tank Regiment) and re-equipped from the storehouses of Rangoon.
By now, some idea of the weakness of Burma command had reached the higher levels of authority in Delhi and London and Lt-General Sir Harold Alexander was on his way to take overall command with Lt-General William Slim to take command of the re-formed Burma Corps.
The end of February had seen the RAF and American Volunteer Corps catch the Japanese Air Force surprise and shoot down some 170 bombers and fighters, gaining command of the air over Rangoon while another Indian brigade and three more infantry battalions were brought in. The decision had been taken on 1st March to make every effort to hold Rangoon, by Wavell and Hutton, and the Chinese were advancing against Toungoo.
When General Sir Harold Alexander arrived in Rangoon he immediately decided to evacuate, and the evacuation of all British civilians, Army and RAF administration troops began. Alongside this, docks, oil installations, workshops and factories were destroyed. By the afternoon of 7th March, the city was burning and the last train had pulled out to the north and the last transports had left for Calcutta.
The Japanese arrived on the 7th March, and had looped around the northern edge of the city and entered from the west, very nearly cutting off and capturing General Alexander but the removal of a vital roadblock allowed the remaining British troops to escape.
As soon as General Sakurai, commanding the Japanese army, realised the British had left Rangoon he ordered pursuit up the only usable road, the Prome road, but was met by strong and organized resistance from the 17th Division which was now under the Command of General Slim. This slowed the Japanese advance and at Toungoo the 200th Chinese Division had stopped the Japanese on the banks of the Sittang.
By March 26th, however, the Chinese casualties were so great that they had to pull back and General Slim ordered the 17th division into the attack to take the pressure off the Chinese. The 17th Division drove the Japanese back almost to Okpo when it was realised that the Japanese were outflanking them again and they had cut the road at Shwedaung. The 17th Division turned and fought their way back into Prome by the end of the month, the last Chinese having evacuated Toungoo that day but failed to destroy the vital bridge. With Rangoon in Japanese hands, the British and Gurkha garrisons on the Adaman Islands were exposed and they were evacuated on 12th March, the Japanese occupied the islands on the 23rd March.
On 17 March, Major Calvert (17th Division) led a Royal Marine raid on the Irrawaddy port of Henzada and attacked a force of dissident Burmese under Japanese officers. At the same time, the 1st Gloucesters surprised and drove away a Japanese battalion billeted at Letpadan, 80 miles south of Prome, inflicting heavy casualties. Heavy Japanese air attacks had driven the RAF out of Burma between 21st and 27th March, with 97 RAF aircraft lost, by this time the Japanese had lost some 291 aircraft.
Withdrawal from Burma
With Toungoo captured by the Japanese, the Japanese army commander General Lida planned to advance north along three rivers. Along the Irrawaddy against the Burma Corps, the Sittang against the Chinese fifth army and along the Salween against the Chinese sixth army.
The Japanese forces on the rear flank had taken Mauchi by the beginning of April and were driving up towards Bawlake and Loikaw. The Japanese outflanked and scattered the Chinese 55th Division by the middle of the month, cut the escape routes behind the remnants by racing along the narrow tracks across the Salween and on 21st April reached and occupied Hoping. The Chinese Sixth army was by this time disintegrating and its commander took his remaining units and headed east and then north back into China. The road to Lashio, the only line of supply and communications for the Chinese armies was now open to attack.
General Slims' forces were well-disposed and organised for a strong defence of the country east of Magwe, but were without air cover, the Japanese air forces having driven the RAF and American Volunteer groups out of Burma. General Ilda's forces closed on the British and attacked. On 16th April, Slim was forced to begin a withdrawal after first ordering the destruction of millions of gallons of oil, which turned Yenangyaung's oil installations and storehouses into one vast sheet of flame.
The Burcorps held the Japanese south of Mandalay assisted by the Chinese 65th Army but when Alexander realised that Lashio was about to fall he decided to concentrate on the defence of India. He ordered Slim to withdraw across the Irrawaddy to Kalewa and after some problems getting the main forces across the Ava brigade all went well until it was learned, on 29th April, that the Japanese had not only captured Lashio and the Burma road was cut, but had outflanked Burcorps once more. They would capture Monywa by 1st May.
The Chinese 5th Army poured north after holding the central Japanese thrust for the last days of April, and had at one point reoccupied Taunggyi and threatened the Japanese advance on Lashio by driving east.
Stilwell's forces suffered from a breakdown of administration and disintegrated. Stilwell escaped back to Shwebo and was forced to walk to the Chindwin and through the hills to Imphal and then Assam.
The Japanese drive continued on the western flank, along the coast to Akyab and along the Chindwin driving Burcorps back towards Assam. On 12th May the monsoon broke and stopped the Japanese pursuit dead in its tracks as well as turning the British retreat into a misery of soaking, mud-caked bone-chilling discomfort.
Some transport struggled out from India to meet the Columns and managed to get most of the very sick and wounded aboard. The survivors of Burcorps struggled back into India after an epic retreat of a thousand miles. It had lasted five and a half months and cost 10,036 British, Indian and Gurkha Soldiers.
By 2nd May all Burma was under Japanese control.