The latest in the RCTS Locomotives of the LMS Series, this long awaited first of two volumes covers the design, development, construction and operation of one of the most well known and largest classes of steam locomotives ever to run on the railways of Great Britain. Authored by the well known and highly respected locomotive historian John Jennison, the book maintains the very high standard of detail and accuracy which is the hallmark of RCTS publications. Lavishly illustrated with black and white photographs from the introduction of the class through until the 1950s and with many diagrams and tables of data.