The document discusses the evolution of the coal sector in India from pre-independence to post-independence. It covers key events like the formation of major coal companies and nationalization of the coal industry. The coal sector was nationalized in two phases in 1971-72 and 1973 to address issues like fragmentation and lack of investment. This led to the formation of major public sector companies like Coal India Limited, which now dominates coal production through its several subsidiaries. Reforms in the coal sector since 1993 have allowed captive coal mining by private and public sectors.