The Royal Navy found wartime work for any serviceable old destroyer

What was the oldest destroyer class the Royal Navy might still use in World War II?

Any serviceable class could find work; if the ship still floated, the Royal Navy would use it in an escort or secondary role.

The Royal Navy's need for hulls was broad enough that age alone did not remove a serviceable ship from consideration. An old destroyer might no longer belong with the fleet screen but could still escort convoys or perform secondary duties. World War I-era sloops retained in World War II provide the comparison for this pragmatic approach. The limiting question was therefore whether the ship could still float and function, not whether it matched the newest destroyer class.