The core of this full length history is the momentous period from the General Strike of 1926 to the nationalization of the mines in January 1947 ... To the treatment of the post Second World War period the authors have added a final chapter assessing the achievements and the problems of the nationalized industry, as well as the role of the miners in the upsurge of industrial militancy that characterized the sixties and seventies." In South Wales Miners' Federation became the South Wales area of the NUM.