On the 1st July 1939 the then Private John Roderick received his commission as Second Lieutenant.  After volunteering for the Commandos he joined No 2 Commando 3 troop. On the St Nazaire raid he commanded an assault party of commandos embarked on board HMS Campbeltown.

During the raid Lieutenant Roderick was shot through his thigh but continued with the operation, until being wounded again in the head by the explosion of a grenade. With ammunition running low he and the others in his party, several of whom were also injured, decided to hide but were discovered in the morning just before the hidden explosives on the Campbeltown exploded. They were then taken in captivity to a hospital in Le Baule. 

Lieutenant Roderick took a keen interest in medicine during recovery from injuries in captivity. He worked as an orderly at a Prisoner of War Hospital gaining valuable medical experience.
On repatriation to the United Kingdom in 1945 he applied and was accepted for a medical course at St Mary's. He graduated Licentiate of the Royal College of Physicians (LRCP), with later Membership of the Royal College of Surgeons (MRCS), and became a well respected General Practitioner. 

He was awarded the Chevalier de Legion d'Honneur by the French Government.