Following the establishment of Manchukuo, the Kwantung Army launched an operation to secure its southern frontier with China by attacking and capturing Shanhaiguan Pass at the Great Wall on 3 January 1933. The province of Rehe, on the northern side of the Great Wall, was the next target. Declaring the province to be historically a portion of Manchuria, the Japanese Army initially hoped to secure it through the defection of General Tang Yulin to the Manchukuo cause.