During the early years of the Chinese People's Republic, Manchuria was usually referred to as the Three Eastern Provinces, which included Liaoning (also known in early years as Fengtien), Kirin and Heilungkiang. At times, a fourth province, Jehol, was also considered part of the region. In fact, since the occupation by the Japanese in 1931, Manchuria has been generally defined to cover the area of these four provinces, rather than that of the three. This was true not only under the Manchoukuo regime, but also under the administration of the Nationalist Government from 1945 to 1948, when the entire region of Manchuria was subdivided into nine provinces, and also under the Communist administration after 1948.