Korean Timeline By andrea_002 Jun 25, 1950 The U.N Security council imposed military sanctions on North Korea Jun 25, 1950 North Korea Invaded South Korea Jun 28, 1950 The fall of Seoul, South Korea's Gov. moved to Daejeon Aug 1, 1950 South Korean and the UN forces established Nakdonggang defense line. Sep 15, 1950 South orean and the UN forces carried out Operation Chromite. Oct 19, 1950 South Korean and the UN forces captured Pyeongyang Oct 25, 1950 The communist Chinese forces entered the Korean war