By the time 3 RAR arrived in the theatre, the KPA had been broken and were in rapid retreat, with MacArthur's forces conducting a successful amphibious assault at Inchon and breakout from the Pusan 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 into North Korea. Although the KPA had suffered heavily in the preceding weeks, they continued to resist strongly. The 27th British Commonwealth Brigade moved from Kumchon, with the Argylls capturing Sariwon on 17 October, killing 215 KPA 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.