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.

Clemens Palme Dutt was the elder brother of Rajani Palme Dutt. Both were active in the Communist Party of Great Britain. Clemens worked as a journalist, translator and editor, in particular of the works of Marx and Engels. The brothers’ Communist ideals were influenced from an early age by their father Dr Upendra Krishna Dutt’s activities as a doctor in a working-class part of Cambridge. While at university, Clemens and Rajani were involved with the Socialist Club where both came to the attention of the British authorities and remained under constant surveillance. Both brothers were founding members of the Communist Party of Great Britain (CPGB).

In the 1920s, both brothers were writing for Labour Monthly and for a time Clemens took over from his brother as editor. In the 1920s, he became actively involved with the Indian independence movement. Working as a journalist in London, he wrote in particular on India and the Indian independence struggle. In July 1923, he visited Berlin from Moscow, where he became closely associated with M. N. Roy, who was heading the Indian section of Comintern. He returned to London later that year under instructions from Comintern to assist Shapurji Saklatvala. In 1925, the CPGB established its own colonial bureau, which Clemens Palme Dutt headed. The bureau attempted to form connections in India, Palestine, China, Egypt and Ireland. He became the link between the CPGB colonial bureau the Comintern’s Indian section and Indian Communists in Europe and India. In 1927, together with N. J. Upadhyaya and Ajoy Banerji, he founded the Indian Seamen's Union in London. By then he was also on the London Council of the Workers' Welfare League of India, working in close cooperation with Saklatvala. During this period Palme Dutt visited Liverpool several times to help with the organization of Indian seamen by local Communists active in the port.

In March 1928, Clemens Palme Dutt was asked by Reginald Bridgeman to join the Executive Committee of the British Section of the League Against Imperialism. In 1928, Palme Dutt returned to Moscow as a member of a sub-committee of the Executive Committee of the Comintern to advise on the Indian situation. In the 1930s, he worked on the editorial staff of the Daily Worker, the organ of the Communist Party of Great Britain, and acted as the Chairman of the Indian Section of the Communist Party of Great Britain. He also represented the Indian Seamen’s Union on the Executive of the League Against Imperialism. Palme Dutt worked as part of the Meerut Prisoners’ Defence Committee. In August 1930, he replaced Percy Glading as head of the Colonial Department of the CPGB. In 1930, together with Saklatvala, he helped to found the Workers' Section of the London Branch of the Indian National Congress. In June 1931, he was part of a sub-committee of the Colonial Bureau of the CPGB to organize Indian students in Britain.

In late 1931 he moved to Berlin and later to Moscow where he met Violet Lansbury (daughter of George Lansbury, leader of the Labour Party in the early 1930s) whom he married in 1936 and with whom he had a daughter. During the Spanish Civil War, Palme Dutt worked together with Krishna Menon and the India League to collect donations for an ambulance for Spanish Republicans. By early 1939 Palme Dutt, his wife and daughter had returned to Britain permanently. He continued to work for the CPGB, addressing meetings and writing articles.

Shah Abdul Majid Qureshi was born in a village in Sylhet, the eldest of three brothers and a sister. His father was forced to sell his land after spending much of his income on educating his sons, and the family lived in impoverished circumstances. To escape a life of hardship and help his family, Qureshi decided to follow the example of many of his fellow Sylhetis and try to get work on a ship with a view to migrating to America or Britain. With this in mind, he left for Calcutta in 1934. After various failed attempts, he finally managed to escape from a ship docked at Tilbury, making his way to east London where he found lodgings with other recently arrived Sylhetis.

Qureshi began his working life in Britain selling chocolates in pubs. He soon moved on to working in various Indian restaurants (including the Bengal Restaurant in Percy Street) and, in 1938, opened his first restaurant, Dilkush Delight, in Windmill Street, Soho. By 1944, he owned a different restaurant off Charlotte Street. This became known as the 'India Centre' because numerous politically active South Asians congregated there for meetings. During this period, Qureshi himself became involved in political and welfare activities concerning the South Asian community in London. He was an active member of the Hindustani Social Club and co-founder (with Ayub Ali) and President of the Indian Seamen's Welfare League. He also attended some India League meetings. A Muslim, Qureshi worshipped at the East London Mosque and helped form the London Muslim League with Abbas Ali.

Qureshi married on his first return trip to Sylhet in 1946 and eventually, in the 1970s, brought his wife and children to England where the family remained.