After leaving Berkhamsted School, in 1902 Lyster joined HMS Britannia to train for a naval career. In July 1909 he was posted to HMS Drake and later to Grafton. From 1912 he specialized in gunnery, training at HMS Excellent, the gunnery school at Portsmouth,[1] and saw active service in the First World War, his ship fighting at Gallipoli in 1915.[2]
Lyster was appointed a Naval Member of the Ordnance Committee in 1929 and given command of the cruiser HMS Danae in 1932.[2] He went on to command the 5th Destroyer Flotilla in 1933 and the Royal Navy Gunnery School at Chatham in 1935 before becoming director of training and staff duties at the Admiralty in 1936.[2] He was given command of the aircraft carrier HMS Glorious in 1937 and was made Aide-de-camp to the King in 1939.[2]
In the Second World War Lyster was initially rear-admiral in charge of HM Dockyard Scapa Flow and then from 1940 saw further active service as rear-admiral in charge of the Aircraft Carriers in the Mediterranean Fleet.[2] He is notable for drawing up the attack plan for the Battle of Taranto, beginning in 1935 on the instructions of Admiral Sir Dudley Pound, and for putting it into execution in November 1940.[3] In 1941 he was appointed as Fifth Sea Lord and Chief of Naval Air Services and Commander of the Aircraft Carriers in the Home Fleet, with his flag in HMS Illustrious, and in 1942 he commanded air operations during Operation Pedestal, for which he was appointed a Commander of the Order of the British Empire.[1] His last appointment was as Flag Officer, Carrier Training, in 1943 before he retired in 1945.[2]