 However, there is increasing support that the industrial revolution was reliant on harnessing the energy and materials provided by Wales and, in that sense, Wales was of central importance.Historian Kenneth Morgan described Wales on the eve of the First World War as a "relatively placid, self-confident and successful nation".The output from the coalfields continued to increase, with the Rhondda Valley recording a peak of 9.6 million tons of coal extracted in 1913.