 By the time 3 RAR arrived in the theatre , the North Koreans had been broken and were in rapid retreat , with MacArthur 's forces conducting a successful amphibious assault at Inchon and breaking out along the Naktong perimeter on the southern tip of the Korean peninsula . A steady advance began , driving the North Koreans northwards towards the 38th Parallel . The 27th British Commonwealth Brigade was attached to the US 1st Cavalry Division , under the command of Major General Hobart R. Gay . On 16 October the brigade took over as the vanguard of the UN advance up the west coast . Although the North Koreans had suffered heavily in the preceding weeks , they continued to resist strongly . The 27th British Commonwealth Brigade moved 70 kilometres ( 43 mi ) from Kumchon , with the Argylls capturing Sariwon on 17 October , killing 215 North Koreans and taking many prisoners for the loss of one man killed and three wounded . The British and Australians then passed to the command of the US 24th Infantry Division on 21 October , under the overall command of Major General John H. Church , while the US 1st Cavalry Division remained in Pyongyang to complete its capture . The brigade was ordered to seize Chongju . 
