The operation began on 3 October with a British assault on one of the other dominant features, Hill 355 (known as Kowang San or “Little Gibraltar”). Then, on the morning of the 5th, 3RAR attacked Hill 317 (Maryang San). The Australian force approached Hill 317 through rugged countryside at 4 am, under a heavy cloak of mist. At 10 am, the mist began to lift, exposing the Australian advance. However, the communists briefly hesitated before firing, which allowed 3RAR to capture the first line of defences in a fierce burst of fighting. The following morning 3RAR drove the communist forces from their position atop the hill, but they had to resist enemy counter-attack. The crest of the Hill 317 was secured on 6 October, after which the Australians assisted the British to take a lesser feature, Hill 217. This was finally achieved on the morning of 8 October.
Operation Commando was strategically important to the UN forces because if Maryang San was secured, the Chinese would be forced back two or three kilometres, thus losing their view of the Imjin salient. This battle was also significant as it was thought to be the last chance for the UN forces to position troops before the ceasefire and armistice negotiations.
There had been two previous attempts to take Maryang San by American troops, both of which had been unsuccessful. However, over a fiercely fought battle, against superior enemy numbers, UN troops were able to gain and secure the hills 317 (Maryang San) and 355 (known as Little Gibralter).
The official historian for the Korean War, Robert O’Neill, wrote of this battle: “In this action 3RAR had won one of the most impressive victories achieved by any Australian battalion. In five days of heavy fighting 3RAR dislodged a numerically superior enemy from a position of great strength. The Australians were successful in achieving surprise on 3 and 5 October, the company and platoon commanders responded skilfully to Hassett’s directions, and the individual soldiers showed high courage, tenacity and morale despite some very difficult situations, such as that of D company when the mist rose on 5 October and those of B and C Companies when the weight of enemy fire threatened their isolation of Hill 317 on 7 October … The victory of Maryang San is probably the greatest single feat of the Australian Army during the Korean War.”
By 5 November, after the Australians were withdrawn to recuperate, Maryang San had been recaptured by the Chinese. It was a terrible blow to morale for those who had fought long and hard to capture it. The tactically important ground of Maryang San remained in the hands of Chinese forces for the rest of the war. Photo: Informal group portrait of non-wounded survivors of the 5th Platoon, B Company, 3rd Battalion, The Royal Australian Regiment (3RAR) after the company was withdrawn from the line at the end of the Battle of Maryang San in October 1951. The 5th Platoon helped capture the Hinge feature and held it through days of heavy shelling and human wave assaults. Identified are 5400049 Sergeant Ray Norman Parry MM, Platooon Commander (is wearing the light coloured undershirt); 1400149 Corporal John Park (white shaving cream on his face; 1400170 Lieutenant Russell John McWilliam (?) (left of Park, wearing dark singlet); Cooke (probably 6400024 Cpl Stanley Denistoun Cooke); 3400182 Private Raymond James ‘Tubby’ Hellings, 5 Platoon runner (smiling,without shirt, behind Park). The shirtless soldier, front, right, is a reinforcement who did not fight at Maryang San. Parry, Park and Cooke and several others in this portrait had also fought at the Battle of Kapyong.