First turning point was intro to France

Sen’s father, an active Communist Party leader, was anti-British. He influenced Sen about France being very advanced in art, human rights and camaraderie. Adolescent Sen got immersed into French art and culture while going to Chandernagore, the erstwhile French territory across the Ganges river from his home. Drawing and painting had become a part of his life by then.

INDIA’S BLOODY INDEPENDENCE
IN 1947
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.