The Chinese Spring Offensive aimed to recapture Seoul, and the lower Imjin River was the gateway. The 29th British Independent Infantry Brigade Group, commanded by Brigadier Tom Brodie, held a twelve-mile frontage along the river -- far wider than doctrine recommended for a brigade. The 1st Battalion, Royal Northumberland Fusiliers held the right, the Glosters the left, and the 1st Battalion, Royal Ulster Rifles the center, with the Belgian United Nations Command battalion in reserve. When the Chinese 63rd Army began crossing on the evening of April 22, they came in waves, using the fords and shallows that centuries of Korean farmers had mapped. By midnight, the brigade's forward positions were under assault from three directions.

Lieutenant Colonel James Carne rallied his Glosters on Hill 235, a rocky prominence they would defend for over sixty hours. Chinese troops swarmed the slopes in human-wave attacks throughout the night, falling back at dawn only to return after dark. By April 24, the Glosters were surrounded and running low on ammunition. Attempts to relieve them failed -- the terrain and Chinese positions made armored advance impossible. Carne ordered his men to break out in small groups on the morning of April 25. Of roughly 650 men in the battalion, only 67 made it back to UN lines. Carne himself was captured and spent two years in a Chinese prisoner-of-war camp. He was awarded the Victoria Cross for his leadership during the battle, while the unit received a United States Presidential Unit Citation.

The 29th Brigade's stand was not a victory in the conventional sense. The brigade suffered over 1,000 casualties, with the Glosters nearly annihilated. The Belgian battalion lost 5 killed and 45 wounded while covering the withdrawal. The Royal Northumberland Fusiliers and the Royal Ulster Rifles fought their way back to prepared positions south of the river after fierce rearguard actions. But the three days the brigade bought proved decisive. The Chinese 63rd Army was so badly mauled that it could not maintain its advance on Seoul, suffering an estimated 10,000 casualties. The offensive stalled, and Seoul remained in UN hands for the rest of the war.

The battlefield lies roughly 60 kilometers north of Seoul, in the hilly terrain where the Imjin River bends southward before joining the Han. A memorial to the Glosters stands on Hill 235, now known as Gloster Hill, maintained by the South Korean government. Each April, veterans and their descendants gather for a commemoration service. The battle holds a particular place in British military memory -- it is one of the few Korean War engagements widely known in Britain, a reminder that the "Forgotten War" claimed British lives too. The Glosters' stand has been compared to Rorke's Drift and Thermopylae, though such comparisons risk obscuring the specific courage of men fighting in Korean hills far from home, in a conflict many of them barely understood.