Born in Plymouth, England, Frederic John Walker enlisted in the Royal Navy in 1909. After passing through the Royal Naval Colleges in Dartmouth and Osborne, Walker went to sea as a midshipman aboard the dreadnought HMS Ajax. Walker was assigned to the destroyer HMS Mermaid in 1916, conducting anti-submarine operations off the Belgian coast, until he joined HMS Sarpedon on convoy duty the following year. Post-War, he married Jessica Eileen Ryder Stobart, and had four children with her. Walker began specializing in anti-submarine warfare in the 1920s, and was considered an expert by the early 1930s. Promoted to commander in 1933, he received his first command of HMS Shikari that May. This was followed by a stint on the China Station in HMS Falmouth, and then the post of Experimental Commander at the anti-submarine school at HMS Osprey in Portland. Walker was saved from early retirement by the outbreak of World War II, and was on the staff of Admiral Ramsey during the evacuation of Dunkirk. Walker was finally given command of the 36th Escort Group in October, 1941, and immediately proved his tactics with the successful defense of convoy HG 76 in December, sinking four U-boats that attacked the convoy. Walker earned the Distinguished Service Order for the action. The 36th would score three more confirmed kills with Walker before he was given a shore command in 1942, and promoted to Captain. In April, 1943, Walker was given command of the 2nd Support Group, a hunter-killer squadron of ships, that operated independently from, but in support of convoys. Under Walker, 2SG would gain fame as the aces of the Battle of the Atlantic, scoring their first kill on 1 June. Walker and 2SG claimed sixteen U-boat kills before June, 1944, when they joined the anti-submarine defenses of the Normandy landings. On 7 July, Walker suffered a stroke, believed to have resulted from exhaustion, and he died two days later. He was buried at sea off Liverpool, with his command unable to attend, due to having been redeployed. With twenty confirmed U-boat kills, Walker was the most successful anti-submarine commander in history. A statue of him was erected in Liverpool in 1998.