Charles Ralfe was born on 22 November 1894, the youngest son of Richard Charles Thompson and Dorothy Clark, at Shiney Row, Penshaw, County Durham. He was educated at Osborne and Dartmouth, and went to sea as a midshipman on the battleship Monarch in 1911. He learned to pilot an airplane, and when the first world war broke out, he attempted to get into the naval aviation program, but was denied. He ended up joining the submarine service. He was in command of submarines almost continually from 1918 until 1931. In 1931 he was posted to Fort Blockhouse, the headquarters of the submarine service. Soon he was asked by Admiral Sir Arthur Waistell, Commander-in-Chief, Portsmouth to join him as his Flag Lieutenant. This is a job dedicated to the smooth running of the Commander-in-Chief's daily program. "Tommy" did such a fine job, he was kept on when a new Commander-in-Chief, Admiral Sir John D. Kelly came to Portsmouth in 1934, and in all he served five years there. In August 1936, Admiral Kelly retired, and The First Lord, Sir Samuel Hoare was scheduled to pay an official visit to the Mediterranean in the Admiralty yacht Enchantress, and "Tommy" was appointed Flag Lieutenant for this cruise.
When the Enchantress completed her cruise, and returned to England, it became apparent to the Board of Admiralty that a permanent Flag Lieutenant was of great value, and in 1936, this job was offered to "Tommy", whereupon he moved to London. Hoare was replaced by Duff Cooper, who was replaced by Lord Stanhope, and finally, on 3 September 1939, Winston Churchill became the First Lord of the Admiralty, again, and on 10 May 1940, he also became the Prime Minister, with the resignation of Neville Chamberlain.|
Lieutenant Commander Charles Ralfe Thompson was now 45 years old, and with 29 years service, he was due to retire from the active list in a few weeks.
When Churchill moved to 10 Downing Street, "Tommy" remained at the Admiralty, however, whenever Churchill decided to go anywhere, "Tommy" was summoned to go with him. In July, a request came from Downing street for his permanent attachment to Churchill's staff, and he moved to new quarters at Storey's Gate, and from then on was rarely away from the Prime Minister's side.