Vice-Admiral Kenneth Gilbert Balmain Dewar, CBE was an officer of the Royal Navy. After specialising as a gunnery officer, Dewar became a staff officer and a controversial student of naval tactics before seeing extensive service during the First World War. He served in the Dardanelles Campaign and commanded a monitor in home waters before serving at the Admiralty for more than four years of staff duty. After the war ended he became embroiled in the controversy surrounding the consequences of the Battle of Jutland. Despite this, he held a variety of commands during the 1920s.

HMS Royal Oak was one of five Revenge-class battleships built for the Royal Navy during the First World War. Completed in 1916, the ship first saw combat at the Battle of Jutland as part of the Grand Fleet. In peacetime, she served in the Atlantic, Home and Mediterranean fleets, more than once coming under accidental attack. Royal Oak drew worldwide attention in 1928 when her senior officers were controversially court-martialled, an event that brought considerable embarrassment to what was then the world's largest navy. Attempts to modernise Royal Oak throughout her 25-year career could not fix her fundamental lack of speed and, by the start of the Second World War, she was no longer suitable for front-line duty.