Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Field Marshal Sir Archibald James Halkett Cassels GCB, KBE, DSO (28 February 1907 - 13 December 1996) was Chief of the General Staff, the professional head of the British Army.Educated at Rugby School and the Royal Military Academy, Sandhurst he was commissioned into the Seaforth Highlanders in 1926.He served in World War II initially as brigade major of 157th (Highland Light Infantry) Brigade in France.