Mary Carpenter was the daughter of a Unitarian Minister, Lant Carpenter, whose family moved to Bristol in 1817. In 1833 the Brahmo Samaj Reformer, Raja Rammohun Ray, visited Bristol and was an important influence upon Mary Carpenter, encouraging an interest in India. Carpenter moved into Red House Lodge in Bristol in 1858 and entertained a number of Indian visitors to Britain, including Satyendranath Tagore, the elder brother of Rabindranath, who arrived in Britain in 1863 and was the first Indian to join the ICS through the competitive ranks, his companion Manomohun Ghose, Joguth Chunder Gangooly, an ordained minister from Boston, and Rakhal Das Haldar who visited Britain for education in the 1860s.

Mary Carpenter visited India four times, the first was in 1866 where she was accompanied by Manomohun Ghose, returning to India after having been called to the Bar, and the daughter of Dr Goodeve Chuckerbutty from Calcutta who had been sent to England for education. Her first port-of-call was to Satyendranath Tagore in Bombay, and on this trip she met Sasipada Banerji who was to return the visit in 1871.

During her third visit to India in 1870, Keshub Chunder Sen discussed with Carpenter the idea of forming an association in Britain. Sen visited her in Bristol in June 1870 and in September 1870, Mary Carpenter inaugurated the Bristol Indian Association. This Association was subsequently renamed the National Indian Association and was designed to promote social reform (particulary female education) in India and provide a meeting place for Indian visitors to Britain. In January 1871, Carpenter began producing the Journal of the National Indian Association. After her death in 1877, the headquarters of the Association were transferred to London.

Sukhsagar Datta was born in Bengal to father Dwijadas Datta and mother Muktakeshi. He was the youngest of five children. His early life and decision to move to England was very much influenced by the actions of his brother Ullaskar. In 1908, Ullaskar was arrested for making a bomb which was used in the attempted assassination of a local magistrate in Alipore; the magistrate survived but two British women died in the attack. His following death sentence was reduced to life imprisonment and he was released twelve years later. The arrest affected the careers of his father and other brother, Mohini Mohan, and as a consequence Sukhsagar was sent to England in 1908.

In London, Datta enrolled at the London Tutorial College, where he met the writer David Garnett. In The Golden Echo (1953), Garnett describes several meetings and walks with Datta and his two other Indian friends, Niranjan Pal and Ashutosh Mitter. He also describes how Datta introduced him to Vinayak Damodar Savarkar at India House, Highgate (at this time, Krishnavarma was living in Paris). After the assassination of Curzon Wyllie and once India House was closed down, Datta and Savarkar shared a flat 'over a small and extremely dirty restaurant in Red Lion Passage' (Garnett, 148). After Savarkar left for Paris, Datta stayed on a bit longer. The two must have remained in touch, though, because Savarkar persuaded Datta to join Abdul Karim’s resistance against the Spanish in Morocco. However, Datta never made it there and returned to London from Algiers. He then ended all contact with Savarkar.

Datta married Ruby Young on 25 September 1911 and the two of them moved to Milan where Datta wanted to pursue a singing career. However, they soon returned to Bristol where Datta enrolled at the Merchant Venturers' Technical College in 1913 or 1914. He graduated in 1914 and joined the University of Bristol Medical School, where he qualified as a doctor in 1920. He first worked at the Bristol General Hospital in 1920, then the Southmead Infirmary in 1921 and finally the Stapleton Institution (now called Manor Park Hospital) where he stayed until his retirement in 1956.

Datta joined the Labour Party in 1926. He was vocal during the Labour Party Conference in 1944, and passionately spoke in favour of Indian Independence. He became chair of Bristol North Labour Party in 1946. After Indian independence in August 1947, Datta founded the Bristol Indian Association. He died at Southmead Hospital, Bristol, on 3 November 1967. 

Born in Bristol in 1871, Albion was the son of Sasipada Banerji, the Brahmo Samaj reformer and friend of Mary Carpenter. Upon his birth, he was hailed as the first Brahmin baby born in Britain and a letter was sent to the Queen by Mary Carpenter informing her of his birth. The family returned to India in 1872 but Albion was later to return to the UK for studies and to compete for the ICS. He had been educated at Calcutta University and then joined Balliol College, Oxford. He passed the ICS exams in 1894 and his first posting in 1895 was as Assistant Collector and Magistrate in Madras.

Subsequent posts that Banerji took up included the Diwan of Cochin (1907-14), the Diwan of Mysore (1922-7), and Foreign and Political Minister in Kashmir. At the Delhi Durbar of 1911, Albion was awarded the Companion of the Indian Empire (CIE).

Banerji was Honorary Treasurer for the World Congress of Faiths, 2nd International Congress of the World Fellowship of Faiths, London, 3-18 July 1936.

Keshub Chunder Sen was a Brahmo Samaj reformer. He visited Britain for six months in 1870. During this trip, Sen toured Britain to deliver sermons and met with a variety of political leaders, including W. E. Gladstone. Sen met Queen Victoria, who later presented him with two books.

On a visit to Bristol. Sen stayed at the house of Mary Carpenter. It was during this meeting that they decided to form the National Indian Association in aid of Social Progress, which was run by Carpenter in Britain.

Upon his return to India, Sen was involved in controversy when he arranged the marriage of his daughter (Sunity Devee) to the son of the Maharaja of Cooch Behar, despite the fact that she was only thirteen years old and violated the reforms that he and the Brahmo Samaj had been campaigning for.