Sen’s first job in France was as a sweeper in an art lithography studio 10 km from Paris. With enormous initial struggle and timely help from kind scientist Dr Pyne, he managed to stay on in France permanently, beyond the 3 months visa granted to him. At the same time he was studying at École nationale supérieure des Beaux-Arts and the School of Design ESAG (Penninghen). In 1974 he had his first solo art exhibition in Paris.
When India was partitioned 1947 to create Pakistan, a new country for Muslims, about 20 million people of Bengal and Punjab were displaced and brutally victimized. Sen’s wealthy, literate family had huge landed property in erstwhile East Bengal, the present Bangladesh, which was carved out to be East Pakistan for Muslims. So for being Hindus Sen’s family was overnight evicted from their home. Without taking any possessions, they fled for their lives amidst people warring over religion, and so became squatted refugees in West Bengal.