Following the North Korean invasion of South Korea on 25 June 1950, a UN counter-offensive had reached the North Korean border with China. Fearing for its own security, China intervened with three offensives between October 1950 and January 1951 which pushed the UN forces south of the original border between North and South Korea along the 38th Parallel and captured Seoul. A fourth offensive in mid-February was blunted by UN forces in the Battle of Chipyong-ni and Third Battle of Wonju. At the end of February the UN launched a series of offensive operations, recapturing Seoul on 15 March and pushing the front line back northwards. In early April Operation Rugged established the front in a line that followed the lower Imjin river, then eastwards to the Hwacheon Reservoir and on to the Yangyang area on the east coast, known as the Kansas Line. The subsequent Operation Dauntless pushed out a salient between the Imjin river as it dog-legged north and the Hwacheon Reservoir, known as the Utah Line.
The deployment of UN forces during the initial stages of the Spring Offensive. Note the importance of 29th Brigade's position for stopping a direct advance on Seoul.
On 22 April the front line in the west along Lines Kansas and Utah was held by the United States Army (US) I Corps comprising, from west to east, the South Korean Republic of Korea Army (ROK) 1st Division, the US 3rd Division with the attached British 29th Brigade, the US 25th Division with the attached Turkish Brigade and the US 24th Division. The 29th Infantry Brigade, commanded by Brigadier Tom Brodie, consisted of the 1st Battalion Gloucestershire Regiment (Glosters), under Lieutenant-Colonel James P. Carne; the 1st Battalion Royal Northumberland Fusiliers (Fusiliers), under Lieutenant-Colonel Kingsley Foster; the 1st Battalion Royal Ulster Rifles (Rifles), under the temporary command of Major Gerald Rickord; and the Belgian Battalion, under Lieutenant-Colonel Albert Crahay (700 men), to which Luxembourg's contribution to the UN forces was attached. The brigade was supported by the 25 pounders of 45 Field Regiment Royal Artillery (RA) commanded by Lieutenant-Colonel MT Young, the 4.2 inch mortars of 170 Independent Mortar Battery RA, the Centurion tanks of C Squadron 8th King's Royal Irish Hussars under the command of Major Henry Huth, and by 55 Squadron Royal Engineers.
The four battalions of 29th Brigade covered a front of 12 miles (19 km). Gaps between units had to be accepted because there was no possibility of forming a continuous line with the forces available. "Brigadier Brodie determined to deploy his men in separate unit positions, centred upon key hill features" On the left flank, the Glosters were guarding a ford over the Imjin 1 mile (1.6 km) east of the ROK 1st Division; the Fusiliers were deployed near the centre, around 2 miles (3.2 km) northeast of the Glosters; the Belgians, occupying a feature called Hill 194 on the right, were the only element of the 29th Brigade north of the river. Their connection with the rest of the brigade depended on two pontoon bridges about 0.5 miles (0.80 km) apart. These bridges connected the Belgians with Route 11, the 29th Brigade's main line of supply and communication. The Rifles served as the brigade's reserve and were deployed along Route 11. Extensive defensive preparations were not completed because the British expected to hold the position for only a short time. Neither minefields, deeply dug shelters nor extensive wire obstacles had been constructed. The British position on the Imjin river "was deemed safe" but vulnerable in case of an attack.
Chinese Spring Offensive, April 1951
The commander-in-chief of the PVA and North Korean Korean People's Army (KPA) forces in the Field, General Peng Dehuai, planned to "wipe out...the American 3rd Division...the British 29th Brigade and the 1st Division of the Puppet Army...after this we can wipe out the American 24th Division and 25th Division", and promised the capture of Seoul as a May Day gift to Mao Zedong. To achieve the objective Peng planned to converge on Seoul with three PVA army groups and a KPA corps; a total strength of some 305,000 men. The III and IX Army Groups were to attack the right flank of the US 3rd Division and the 24th and 25th Divisions on the Utah Line, east of the Imjin where it turned north. The XIX Army Group on the PVA right flank, west of the Imjin river where it turned north, were to attack the remainder of the 3rd Division and the ROK 1st Division. On the XIX Army Group front, the KPA I Corps and PVA 64th Army would attack the ROK 1st Division, while the 63rd Army would attack on their left, pitting it against 29th Brigade. The 63rd Army comprised three divisions, the 187th, 188th and 189th, with each division comprising three regiments, each of which comprised three battalions. Some 27,000 men in 27 battalions would be attacking 29th Brigade's four battalions, albeit in echelon, one division after the other.