Burma as a separate British colony after its formal separation from British India on 1 April 1937 (Government of India Act 1935 / Government of Burma Act), with its own governor and legislature at Rangoon.
Overrun by Japan in 1942; restored 1945 (military administration, then civil government from October 1945); independent as the Union of Burma on 4 January 1948.
The atlas holds 2 border frames for British Burma — the shape you scrub through changes in 1937 · 1945.
Accessible modern history of Burma covering the colonial separation, the war, and the road to 1948 independence.
The 1942 fall and 1945 reconquest of British Burma in full.