When the Second Sino-Japanese War broke out between China and Japan in 1937, Peking University, Tsinghua University in Beijing and Nankai University in Tianjin moved and merged to form Changsha Temporary University in Changsha and soon later National Southwestern Associated University (國立西南聯合大學), or Lianda (聯大) for short, in Kunming and Mengzi, in Southwest China's Yunnan Province. After the war, the universities moved back and resumed their operation.