It was ringed by significant British and Commonwealth possessions and much of the strategic supplies needed in peace and war had to pass across it: i.e. Persian oil, Malayan rubber, Indian tea, Australian and New Zealand foodstuffs.

[3] At the outbreak of war, Nazi Germany's Kriegsmarine used auxiliary cruisers (converted merchant ships) and the "pocket battleship" Admiral Graf Spee to threaten the sea lanes and tie down the Royal Navy.

In mid-1940, Italy declared war and their vessels based in Italian East Africa posed a threat to the supply routes through the Red Sea.

[6] On 10 June 1940, the entry of Italy into the war introduced a new threat to the oil supply routes from the Persian Gulf, which passed through the Red Sea to the Mediterranean.

In these circumstances, with the Japanese fleet engaged by the United States Navy (USN), the Admiralty planned to send four Revenge-class battleships to Singapore to provide defensive firepower and a British presence.

[10] After the fall of France in June 1940, Japanese pressure on the Vichy authorities in French Indochina resulted in the granting of base and transit rights, albeit with significant restrictions.

[11] The bases thus acquired in Indochina allowed extended Japanese air cover of the invasion forces bound for Malaya and for the Dutch East Indies.

His fleet consisted of the two large carriers Indomitable and Formidable, the small carrier HMS Hermes, the battleships Warspite (recently returned from repairing battle damage received off Crete in America), Resolution, Ramillies, Royal Sovereign and Revenge, two heavy and five light cruisers (including the Dutch Heemskerck), sixteen destroyers and seven submarines.On 31 March Somerville decided to divide the Fleet into two: Force A and Force B.

Addu Atoll, southernmost of the Maldives in the Indian Ocean, 600 miles southwest of Ceylon, met the requirements and it was secretly developed as a fleet anchorage.

On 7 April Somerville was given discretion by the Admiralty to send the slow Revenge-class battleships of Force B all the way back to Kilindini in East Africa, relatively safe from Japanese attack.

"[17] Later, the fleet in the Indian Ocean was then gradually reduced to little more than a convoy escort force as other commitments called for the more modern, powerful ships.

[18] From October 1943, the Eastern Fleet was the maritime component of South East Asia Command, including responsibilities beyond the SEAC area.

As a result, more British aircraft carriers entered the area; added to the force were the battlecruiser Renown, the battleships Howe, Queen Elizabeth, Valiant and supporting warships.

Agreement had been reached, after objections from Admiral Ernest King USN, but new procedures would need to be learnt by naval crews and Fleet Air Arm (FAA) aircrew.

The objective was for the fleet to rendezvous with a group of tankers (escorted by the Dutch cruiser HNLMS Tromp) and practice refuelling at sea procedures.

[20] Admiral King requested that, during April, the Eastern Fleet should engage Japanese forces in their area and hold them there to reduce the opposition to an American seaborne assault on Hollandia and Aitape on the north coast of Netherlands New Guinea.

[citation needed] Saratoga and her destroyers returned to the Pacific from 18 May after what Admiral Somerville called "a profitable and very happy association of Task Group 58.5 with the Eastern Fleet".

[22] The Eastern Fleet was greatly augmented by units intended for the Pacific and on 4 January 1945, the carriers Indomitable and Indefatigable carried out an attack on oil refineries at Pangkalan Brandon in Sumatra (Operation Lentil).

Operation Meridian was a series of air attacks upon the oil refineries at Pladjoe, north of Palembang, Java and at Soengei Gerong, Sumatra.

In addition to the Vice-Admiral commanding, Rear-Admiral Oliver Bevir served as Senior Officer, Royal Naval Establishments, India, from June 1944 to July 1945.