The destroyer, named after Osman Ali Khan, the last Nizam of Hyderabad, was commissioned into the RAN in 1940, although the ship remained the property of the Royal Navy for her entire career.

[4] When the campaign turned for the worse, Nizam and Napier made two evacuation runs to ferry troops from the island to Alexandria.

[2] After repairs were completed, Nizam spent the rest of 1941 escorting Malta Convoys, on bombardment operations in north Africa, and transporting troops to Cyprus and Haifa.

[2] On 21 October 1941 Nizam was part of a convoy which came under Stuka dive bomber attack while evacuating Australian infantry Rats of Tobruk to Alexandria.

At the start of 1942, Nizam and her sister ship, Napier sailed for Singapore to join Nestor as escort for the aircraft carrier HMS Indomitable.

[2] On 22 September, Nizam was assigned to Durban to patrol for Vichy French merchant ships, capturing one and forcing another to scuttle during the week spent in this role.

[2] After delivering the British survivors ashore, Nizam made for Australia, and docked in Melbourne on 18 August for an eight-week refit.

[8] During her time based here, Nizam participated in Operation Cockpit, a carrier air raid on Japanese assets in south-east Asia.

[8] In a tragedy which harked back to that of 21 October 1941, on 11 February 1945, while crossing the Great Australian Bight in poor weather after the refit, Nizam was hit by a freak wave which caused the ship to roll almost eighty degrees to port, and washed ten sailors overboard, none of whom were ever seen again.

[8] During 1945, Nizam was assigned to the Philippines and New Guinea theatres as part of the British Pacific Fleet, during which, her pennant number was changed from G38 to D15.

[8] Nizam earned seven battle honours for her wartime service: "Malta Convoys 1941–42", "Crete 1941", "Libya 1941", "Mediterranean 1941", "Indian Ocean 1942–44", "Pacific 1943", and "Okinawa 1945".