It unexpectedly found itself in control of a very large rear communications area, and the troops on the frontier with Burma, roles for which it had not prepared in peacetime.

The 14th (Light) Division had been raised at Quetta in Baluchistan and was originally intended to form part of the Allied forces in Iraq and Persia.

He informed Lieutenant General Slim that the headquarters of Eastern Army and XV Corps were to exchange places for the offensive.

The only permanently established route across the range was a disused railway track, converted into a road, which linked Buthidaung with the port of Maungdaw on the west coast of the peninsula.

It was originally planned in September 1942 that Akyab would be taken by an amphibious assault launched by the British 29th Brigade, while the 14th Indian Division mounted a subsidiary advance down the Mayu peninsula.

The amphibious part of the plan was dropped because 29th Brigade (which until November 1942 was engaged in the Battle of Madagascar) and the necessary landing craft could not be made available in time.

)[8] The 14th Indian Division, commanded by Major General Wilfrid Lewis Lloyd, began advancing south from Cox's Bazar near the frontier between India and Burma, on 17 December 1942.

Both Slim and the brigade commander (Brigadier George Todd) protested that a complete regiment (of 50 or more tanks) would be required, but they were overruled.

During February, it cleared detachments of the British irregular V Force from the valley of the Kaladan River, where they had been threatening the Japanese lines of communication.

In the first week of March, the third battalion of the Japanese 213th Regiment crossed the Mayu River and attacked Indian 55th Brigade, forcing it to retreat.

In spite of this growing threat to the left flank of 14th Division, General Irwin demanded that another attack be made on the Donbaik position, using the powerful and well-trained British 6th Brigade.

On 10 March, Lieutenant General Slim had been ordered to report on the situation in Arakan, although it was not yet intended that XV Corps headquarters take charge of the front.

Some of the Japanese 55th Division had reinforced the defenders of Donbaik, and in spite of heavy artillery support the 6th Brigade also was unable to deal with the bunkers and suffered 300 casualties.

[15] On 25 March, Lloyd ordered the isolated 47th Indian Brigade to fall back across the Mayu Range, despite Irwin's instructions to hold all ground until the monsoon.

[16] On 3 April, while "Uno Force" (the Japanese 143rd Regiment) pressed northwards up the Mayu River valley, the main body of the Japanese 55th Division ("Tanahashi Force", consisting mainly of the 112th Regiment) crossed the Mayu Range at a point where British officers had regarded the range as impassable and cut the coastal track behind the leading British troops.

Although the British 6th Brigade was still formidable in spite of its recent defeats, Slim was concerned that the other troops on the front were tired and demoralised.

On 11 May, the port was abandoned and XV Corps fell back to Cox's Bazar in India, where the open rice-growing country gave the advantage to British artillery.

The British stand had also bought enough time for the monsoon rains to arrive in force (Arakan receives 200 in (5,100 mm) per annum), dissuading the Japanese from following up their successes.

The average British and Indian soldier was not properly trained for fighting in jungle, which together with repeated defeats adversely affected morale.

The first Chindit raid under Brigadier Orde Wingate concluded about this time, and its successes were widely publicised to counter the depressing news from the Arakan.