Bishnu was born on 10 April 1930 in Shillong, the capital of Assam at that time. The eldest of Dr Birendra Kumar Pal Choudhury and Snehalata Pal Choudhury’s three children. He was educated at the Bengali High School in Dibrugarh and at St. Anthony’s College in Shillong. Bishnu started his medical training in 1948 at the Assam Medical College in Dibrugarh, qualifying in 1953. He gained a Diploma in Ophthalmic Medicine and Surgery at the Eye Infirmary of Calcutta Medical College in 1957, and his Master of Surgery from King George’s Medical University in Lucknow in 1959. He worked as a Consultant Ophthalmologist at MJN Hospital in Cooch Behar for a couple of years before becoming a Registrar in ophthalmology at the NRS Medical College of Calcutta University. In 1961 Bishnu left India, to study for a PhD in physiology under the supervision of Prof. David Whitteridge at Edinburgh University. He researched the role of the corpus callosum and gained his doctorate in 1964. Returning to Calcutta, Bishnu worked as a clinical tutor and a medical officer at the RG Kar Medical College, Institute of Ophthalmology until 1968. In 1966 Bishnu married Anuradha Roma Ghosh, and their daughter, Purba was born in 1967. In 1968 Bishnu took up the position of Research Associate at the Center for Brain Research, in Rochester University, New York, taking his wife and daughter with him. In 1970 Bishnu moved to the UK and became a lecturer in physiology at Cardiff University. Their son, Pushaun, was born in 1972. Bishnu continued teaching physiology and researching the visual cortex until his retirement in the late 1990s. Post-retirement, Bishnu devoted his time to sharing his knowledge and passion for Indian visual arts and culture, teaching courses at Cardiff University’s Department of Life-long Learning, and giving talks at universities all over the UK, including Oxford, Cambridge, Manchester and the City Literary Institute in London. This culminated in the publication of a book, 'Indian Visual Art – a brief account', in 2002. Bishnu was elected a Fellow of the Royal Asiatic Society of Great Britain and Ireland in 1999. Always keen to expand his knowledge and understanding, Bishnu regularly attended talks and lectures at the Oxford Centre for Hindu Studies, the Nehru Centre in London and at the Tagore Centre UK. Bishnu was also very interested in the history of Hinduism, and particularly in the Brahmo Samaj and its founder, Raja Rammohun Roy. He researched and wrote many articles and gave talks on these topics. In January 2015 Bishnu published 'The State of Hinduism in Bengal Today and Yesterday – a Personal Observation'. He wrote a play, 'The King’s Courier', (inspired by Rabindranath Tagore’s play 'Dakghar') which had its world premiere performance in London in November 2014 as part of the ‘Season of Bangla Drama’, and was working on a second play. During the last two months of Bishnu’s life, the symptoms of the pulmonary fibrosis that he was suffering from worsened considerably. He passed away peacefully, at home, surrounded by his family on Sunday 8 March 2015, aged 84.