1936: Boris III of Bulgaria had his hands on the levers of power in more than one sense. Figuratively, he was absolute monarch of his country; literally, his favourite pastime was driving locomotives. His brother, Kyril, was also a railway enthusiast, and when Edward VIII and Mrs. Simpson visited Bulgaria, the two brothers squabbled over who should drive the train.
Source: Duke of Windsor, A King’s Story: The Memoirs of H.R.H. the Duke of Windsor K.G. (1951), pp. 308–9