Radcliffe Line

The Radcliffe Line is the demarcation that separated British India into the dominions of India and Pakistan upon Partition, published on 17 August 1947 — two days after independence. It was the product of the Boundary Commissions established under the Indian Independence Act 1947 and the Mountbatten Plan (the 3 June Plan), and was named after Sir Cyril Radcliffe, the British barrister who chaired both the Punjab and the Bengal Boundary Commissions. Radcliffe, who had never previously visited India and arrived in July 1947, was given roughly five weeks to partition territory inhabited by some 88 million people, with the explicit mandate to demarcate the boundaries of the two parts of the Punjab and Bengal "on the basis of ascertaining the contiguous majority areas of Muslims and non-Muslims," while taking "other factors" into account.

Each Boundary Commission comprised Radcliffe as chairman plus four High Court judges — two nominated by the Indian National Congress and two by the Muslim League. Because the nominated judges divided predictably along communal lines and deadlocked, the decisive determinations fell to Radcliffe's casting authority alone. The Punjab award split the province, dividing the districts of Gurdaspur, Lahore, Amritsar and Ferozepur, while the Bengal award separated West Bengal from East Bengal (later East Pakistan, today Bangladesh) and assigned Calcutta to India. The award also separated Sylhet, transferred to East Bengal following a referendum, and the Chittagong Hill Tracts. The most contested decision was the allotment of the Muslim-majority Gurdaspur district largely to India, which gave India crucial land access to the princely state of Jammu and Kashmir — a point Pakistani historiography cites as evidence of partiality.

Radcliffe destroyed his working papers and refused his fee, returning to England and never speaking publicly in detail about the exercise. The boundary's hurried, unannounced publication contributed to the catastrophic communal violence and the migration of an estimated 10–15 million people across the new frontier, accompanied by mass killings. Portions of the line remained disputed and undemarcated for years; the Bengal sector left enclaves (chhitmahals) unresolved until the India–Bangladesh Land Boundary Agreement of 1974 was finally implemented through the exchange of enclaves in 2015 under the 100th Constitutional Amendment. The Radcliffe Line forms the basis of the present international boundary between India and Pakistan in Punjab and Rajasthan, and between India and Bangladesh, distinct from the Line of Control in Jammu and Kashmir, which arose from the 1948–49 ceasefire and the 1972 Simla Agreement.

For UPSC and other civil-service examinations, the Radcliffe Line appears principally in Modern Indian History and the freedom struggle, often linked to the Mountbatten Plan, the Indian Independence Act 1947, and the consequences of Partition. Prelims questions test who drew the line, the year, and the provinces partitioned; Mains questions probe the criteria of demarcation, the Gurdaspur controversy, and Partition's humanitarian aftermath. Aspirants should distinguish the Radcliffe Line from the Durand Line (Afghanistan–Pakistan), the McMahon Line (India–China), and the Line of Control.