Field Marshal Guthrie was educated at Harrow and RMA Sandhurst. He joined the Welsh Guards in 1959 and in the 60s served with them and the SAS in the United Kingdom, Libya, The Middle East, Malaysia and East Africa. . In 1980 he served briefly in the South Pacific and as Commander British Forces, New Hebrides, recaptured the island of Espirito Santo, which had been seized by insurgents. Currently he is the Colonel to the Life Guards and Gold Stick to the Queen. Guthrie was promoted to the honorary rank of Field Marshal in June 2012.