The Partition of India in 1947 remains one of the most defining and tragic events in South Asian history. This research paper examines the rise and consolidation of communal politics between 1900 and 1947 and analyzes how religious identities were politicized, ultimately culminating in the division of British India into India and Pakistan. It explores the role of colonial policies, the emergence of political organizations such as the Indian National Congress and the All-India Muslim League, the ideological divergences between leaders, and the socio-political developments that intensified Hindu-Muslim divisions. By tracing key events such as the Partition of Bengal, the Lucknow Pact, the Khilafat Movement, and the Lahore Resolution, the study argues that communalism was not an inevitable outcome but rather a historically constructed phenomenon shaped by colonial strategies, elite politics, and mass mobilization. The paper concludes by highlighting the complex interplay of political ambition, identity formation, and colonial governance that led to the eventual partition.