ĀZĀD HIND FAUJ, or Indian National Army (I. N. A. for short) as it was known to the English-speaking world, was a force raised from Indian prisoners of war during World War II (1939-45) to fight against the British. The hostilities had started with the German invasion of Poland on 1 September 1939. The United Kingdom declared war against Germany, and India, then ruled by the British, automatically joined in under the governor-general's proclamation of 3 September 1939. While the smaller Indian political parties such as the Muslim League, Hindu Māhā Sabhā and the Shiromaṇī Akālī Dal were prepared to support government's war effort, Indian National Congress refused to co-operate. A resolution passed by its Working Committee on 15 September 1939, and subsequently endorsed by the All India Congress Committee and the plenary session of the Congress, declared : "India's sympathy is entirely on the side of democracy and freedom, but India cannot associate herself with a war said to be for democratic freedom when that very freedom is denied to her. . . " The resolution demanded that the British government pronounce in unequivocal terms their war aims and "in particular how those aims are going to apply to India and to be given effect to in the present. " Congress-led ministries in eight of the provinces resigned and the party planned a programme of individual satyāgraha or protest. In fact, a group of left wingers in the Congress had already formed a separate party, the Forward Block, under the leadership of Subhās Chandra Bose. This group wanted to take advantage of the situation and to intensify their struggle for independence. Subhās Chandra Bose was arrested on 2 July 1940. He went on an indefinite hunger strike on 29 November and was released on 5 December, but was kept under police surveillance in his ancestral house in Calcutta. Giving the police the slip on the night of 16-17 December, Subhās Chandra Bose reached Berlin on 28 March 1941 after a hazardous journey through north India, Kabul and Moscow. There he made contact with Germany's foreign minister, Joachim von Ribbentrop, who accepted his offer of raising Free India units from Indian prisoners of war. That disaffection against the British existed among Indian troops had been evidenced when a Sikh squadron had refused to embark at Bombay in August 1940, and when Sikh soldiers in some other regiments had refused to wear steel helmets. Subhās Chandra's call to Indian prisoners of war was well received and 1, 200 men, mostly Sikhs, were recruited during the first six months for a training camp set up at Frankenburg. This camp was the precursor of the Āzād Hind Fauj. It was initially named Lashkar-i-Hind or Indian Legion and its strength in the West rose in due course to 4, 500. The name of the political organization corresponding to the Indian Independence League in the East was the Free India Centre.

        Japan's entry into the War on 8 December 1941 and her rapid conquest of Malaya and Singapore, with Thailand's capitulation into neutrality, radically changed the situation so far as India was concerned. Certain Indian nationalist sections such as the Socialist Party and Forward Bloc entertained hopes of liberating the country with Japan's help. Indians, mainly Sikhs, living in Malaya, Singapore and other countries of the region had set up two secret anti-British groups, led by Giānī Prītam Siṅgh and Swāmī Satyānanda Purī, respectively.

        A Japanese officer, Major Fujiwara, head of the field intelligence section in the region, had, even before the declaration of war by Japan, contacted Giānī Prītam Siṅgh and reached an agreement of collaboration with him at Bangkok on 4 December 1941. Following the Japanese advance in North Malaya, Fujiwara and Prītam Siṅgh reached Alorstar on 14 December 1941. It was here that Captain Mohan Siṅgh, a straggler from the 14 Punjab Regiment overrun by the invaders, contacted them. He surrendered on the following day and was asked to restore order in the town. All Indian prisoners of war and stragglers were put under his charge. Kuala Lumpur fell on 11 January 1942 with 3, 500 Indian prisoners of war and Singapore on 15 February 1942 with 85, 000 troops of whom 45, 000 were Indians. Mohan Siṅgh asked for volunteers who would form the Āzād Hind Fauj to fight for freeing India from the British yoke. A large number, again mostly Sikhs, came forward. Mohan Siṅgh established his headquarters at Neeson in Singapore with Lt. -Col. Nirañjan Siṅgh Gill as Chief of Staff, Lt. -Col. J. K. Bhonsle as Adjutant and Quartermaster-General and Lt. -Col. A. C. Chatterjee as Director of Medical Services. The Āzād Hind Fauj, however, was formally established on 1 September 1942 by which date 40, 000 prisoners of war had signed a pledge to join it.

        Meanwhile another organization, Indian Independence League, had materialized under the leadership of Rāsh Behārī Bose, veteran Indian revolutionary, who had escaped to Japan in June 1915 and become a Japanese citizen. He arranged two conferences of Indians in the East to discuss political issues. The Tokyo Conference, 28-30 March 1942, besides establishing the Indian Independence League, resolved to form an Indian National Army. The Bangkok Conference, 15-23 June 1942, formally inaugurated the Indian Independence League adopting the Congress tricolour as its flag. One of the 35 resolutions passed by it invited Subhās Chandra Bose to East Asia. Through another resolution Captain Mohan Siṅgh was appointed commander-in-chief of the Army of Liberation for India, i. e. the Indian National Army. The Indian Independence League, which undertook to supply men, materials and money to the Army, established a Council of Action; with Rāsh Behārī Bose as president and Mohan Siṅgh as one of the four members with charge of the military department. News of the Quit India movement launched by the Congress Party in India in August 1942 afforded further encouragement, and the Āzād Hind Fauj was formally inaugurated on 1 September 1942.

        Difficulties, however, arose soon after. Mohan Siṅgh (now General) was disillusioned regarding the intentions of the Japanese, who wanted to use the Indian National Army only as a pawn and a propaganda tool. He was also dissatisfied with the functioning of the Council of Action and the Indian Independence League, who failed to secure Japanese recognition and official proclamation regarding the existence of the Fauj. The other members of the Council of Action, on the other hand, were unhappy with Mohan Siṅgh for his arbitrariness in military matters. The crisis came on 8 December 1942 when the Japanese arrested Colonel Nirañjan Siṅgh Gill branding him to be a British agent, without informing General Mohan Siṅgh, whose protest was ignored and who was not even allowed to see Colonel Gill. On the same day the three civilian members of the Council of Action resigned. On 29 December 1942, General Mohan Siṅgh was removed from his command and was taken into custody by the Japanese military police. The Indian National Army was disarmed. Efforts to revive it were made by Rāsh Behārī Bose who appointed a committee of administration to manage its affairs.

        Subhās Chandra Bose, popularly called Netājī (lit. respected leader), left Europe on 8 February 1943 and arrived at Tokyo on 13 June 1943. After discussing matters with the Japanese prime minister, General Tojo, he came to Singapore on 2 July 1943. Two days later Rāsh Behārī Bose handed over the leadership of the Indian Independence League to him. On 5 July 1943 Netājī revived the Āzād Hind Fauj, giving it the battle cry "Chalo Delhi" ("March to Delhi") and the salutation “Jai Hind" ("Victory to India"). On 23 October 1943 he proclaimed the setting up of the Provisional Government of Āzād Hind, which was recognized within a few days by nine countries, including Japan, Italy and Germany. On 6 November 1943, the Japanese premier announced the handing over of the Andaman and Nicobar Islands to the Provisional Government. Netājī organized the Fauj into three brigades for taking part in Japan's offensive campaign on India's eastern borders. After initial hesitation of the Japanese field commander, Field Marshal Terauchi, to associate Indians with actual fighting, it was agreed to employ one brigade, as a trial, attaching smaller Indian detachments to different units of the Japanese army as irregulars. Accordingly, a new brigade of three battalions was raised by selecting the best soldiers out of the other three. Commanded by General Shāh Nawāz Khān, its 1st Battalion operated on the Arākān front and had its first notable success in May 1944 when it captured the British post of Mowdok in the Indian territory, about 80 km to the east of Cox Bāzār, and holding it till September 1944 in the face of repeated counter attacks by British forces. The other two battalions also gave a good account of themselves in Falam and Haka area. Meanwhile, Subhās Chandra Bose had brought forward his headquarters to Rangoon. The Japanese commanders, satisfied with the fighting skill and courage of the Āzād Hind Fauj soldiers, associated another Indian brigade in their operations in Imphāl and Kohīmā sectors. The British forces, however, not only withstood the offensive during the winter of 1944-45 but also launched a counter-attack. The Japanese and the Āzād Hind armies retreated fast. Rangoon was occupied by the British early in May 1945. On 16 May, Shāh Nawāz, Gurbakhsh Siṅgh Ḍhilloṅ and many other officers and men of the Āzād Hind Fauj surrendered at Pegū in Lower Burma where after the Āzād Hind Fauj ceased to exist.

        The War ended with Japan's surrender on 14 August 1945. Subhās Chandra Bose died in an air-cash on 18 August 1945. Officers and men of the Indian National Army were brought back to India and were interrogated and divided into three categories : white or loyal in their allegiance to the British throughout; grey or those whose loyalty was doubtful; and black or those who admitted that they had joined the Āzād Hind Fauj. The white were reinstated with benefits of seniority and arrears of pay; the grey were kept under observation and were later graded into either white or black. The black were summarily dismissed and their arrears of pay and allowances were confiscated. Mohan Siṅgh and Nirañjan Siṅgh Gill were set free. Shāh Nawāz Khān, Gurbakhsh Siṅgh Ḍhilloṅ and Prem K. Sehgal were, as a test case, put on trial in open court in the Red Fort at Delhi. They were charged with treason and with waging war against the King. This aroused India-wide sympathy for them. The trial began on 5 November 1945. Eminent lawyers and public men such as Tej Bahādur Saprū, Bhūlābhāī Desāī and Jawāharlāl Nehrū defended the accused in court. There were riots in their favour in several places between 21 and 24 November. The court on 31 December 1945 sentenced all the three to transportation for life. The government, however, yielded to the outburst of popular sympathy and the British commander-in-chief, Sir Claude Auchinleck, quashed the sentence on review.