The sources differ regarding Howard-Johnston's early career, with
The Times saying he spent some time on secondment in France and then was posted to China as second-in-command of In 1940, Howard-Johnston joined the anti-submarine warfare division at the Admiralty, and later the same year was detached to set up an anti-submarine training unit at
Quiberon and then to organise anti-submarine operations in Norway. although not for anti-submarine duties: instead, for the evacuations at
Andalsnes and
Molde. A month later, he was ordered to demolish the port facilities at
St Malo, and received a
Mention in Dispatches for this work. Howard-Johnston was then transferred to command on the north Atlantic convoys, for which he received another Mention in Dispatches – and then in January 1941 the DSO, "for skill and enterprise in action against Enemy Submarines", referring to the sinking of
U-651. He was then transferred to Liverpool, to train others, before being promoted to captain in June 1943, and had been made director of the Anti-Submarine Division at the Admiralty. In 1945, he was given command of the
light cruiser HMS Bermuda, and then from August 1950 to October 1952 was Captain of the
HMS Vernon Torpedo School. In 1951, while at
Vernon, he had to organise the unsuccessful search for , on which his son was serving. In 1953, he was promoted to rear-admiral, and served on the NATO staff before finally retiring. ==Personal life==