Mohan Kumaramangalam was born in London in 1916 to Paramasiva and Radhabhai Subbarayan. He studied at Eton and then at King's College, Cambridge University. He became President of the Cambridge Majlis in Lent 1937 and President of the Cambridge Union in Michaelmas 1938. He was also a member of the Federation of Indian Students' Societies and an active socialist. He was called to the Bar at the Inner Temple and went to India in 1939.

Mohan Kumaramangalam was a member of the Communist Party of India (CPI) until 1966 when he joined the Indian National Congress.

The nephew of J. N. Tata, Shapurji Saklatvala travelled to England in 1905 to recuperate from malaria and to manage the Tata company office in Manchester. He married Sarah Marsh in 1907 (a waitress he had met at the hydro in Matlock where he had been treated). They moved to London in 1907 and Saklatvala joined the Independent Labour Party (ILP) in 1909. In 1921, Saklatvala was adopted as the Labour candidate for Battersea North, despite joining the Communist Party in the same year. In November 1922, he won the seat for Labour and was defeated in December 1923. He regained the seat in October 1924, when he stood as a Communist representative and held the seat until 1929. Saklatvala was the 3rd Asian to become an MP in Britain (all incidentally of Parsee background).

Saklatvala raised Indian issues in Parliament. He was a member of the Indian Home Rule League (founded in 1916). He was also a founder member of the Workers' Welfare League in 1917. This League was initially concerned with the working conditions of Indian seamen in London, but soon widened its objectives to improve the position of all types of Indian workers. He was an influential figure to Indian students in London in the 1920s and 1930s, but was banned from returning to India because of his Communist affiliations. He died in his home in London in January 1936 and was buried in the Parsee burial ground in Brockwood, Surrey.

N. J. Upadhyaya, a Brahmin from a poor family, was born in the Indian State of Nawanagar. A British ‘protected person’ rather than a British citizen by virtue of his birthplace, he arrived in England in 1922, having worked as a schoolteacher, on a Gujarati newspaper, then on the Bombay Stock Exchange, where he accumulated the means to come to England. Unlike many of his more privileged fellow migrants, Upadhyaya arrived without knowledge of the English language but quickly tried to master it. On his arrival in England, he stayed with a fellow Communist, Adela Knight, in Abbey Wood, London, and became involved in political activities.

Considering his lack of proficiency in English on arrival, Upadhyaya’s prominence in the Communist Party and in other workers’ organizations was quite remarkable. For the Communist Party he recruited Indians, organized meetings in London, distributed literature and wrote articles. He was also instrumental in founding the Indian Seamen’s Union in 1925, assuming the role of Secretary, with Shapurji Saklatvala as President. In this role, he encouraged Indian seamen to strike against their pay and conditions and to join unions, and helped deserters to secure jobs in hotels and restaurants in London. Upadhyaya also protested against the application of the Coloured Seamen’s Order to Indians and against police stopping Indians in the street and asking to see their Certificates of Registration. In 1928, he founded the Liverpool Indian Association. According to Indian Political Intelligence surveillance reports, Upadhyaya, known among Communist Party members as ‘Paddy’, would disseminate Communist literature among sailors in the docks by posing as a missionary carrying a Bible with leaflets hidden inside.

Upadhyaya was subjected to police interrogation and generally considered to be a suspicious and potentially threatening figure. His name was on the list of Indians to whom passport facilities should not be granted without previous reference to the India Office, and in 1927, questions were raised in parliament about the possibility of deporting him under the 1920 Aliens Order; as a British protected person, he was technically an ‘alien’ rather than a ‘British subject’ so could legally be deported. The government decided against it ultimately, on the grounds that it would be politically insensitive.

Highly conscious of the wealth and class divisions among Indians in Britain, Upadhyaya encouraged poor Indians to beg money from rich Indians. Despite his working relationship with eminent Communist figures such as Clemens Palme Dutt and Saklatvala, it would seem that Upadhyaya himself remained constrained by his class background, failing to gain admission to circles of more privileged Indians in London. He is reported to have remarked on his suspicious treatment by frequenters of the Gower Street India Club and Indian Students’ Hostel. Little is known of Upadhyaya’s personal life. Surveillance reports describe him as frequenting ‘Soho cafes’ and also suggest that he was an alcoholic. By 1933, reports claim he was no longer involved in Communist politics and even that he was a Government agent! By 1936, he was employed as a paper salesman.