Mountain Ash Rugby Football Club - "the Old Firm" - was formed in 1875 and is based in the Cynon Valley in South Wales. It grew to become one of the strongest Clubs in Wales, and during the years up until the start of the 2nd World War, took on and beat all Wales' "first class" Clubs and some in England. This book provides a summary of each season, including the playing record, newspaper match reports, Glamorgan League triumphs, and gives details of the Club's eight Welsh Internationals and those who left to play professional rugby. It is a compelling read.