Rhehe Province is now the Inner Mongolia Autonomous Region, Hebei Province, and Liaoning Province.

Rehe Province, abbreviated as Rehe and with its capital city of Chengde, is a former provincial administrative region of China, one of the four eastern provinces of Guanwai. The Jehol Special District was set up in January of the third year of the Republic of China (R.O.C.).

Republic of China seventeen years in September, reformed into a province. 1955 July 30, Jehol province was abolished. The jurisdiction was spread over the present Inner Mongolia Autonomous Region, Hebei Province and Liaoning Province.

History of Jehol province:

The national government redrew the area of Jehol province in May, R.O.C. 36, roughly restoring the previous administrative division. Four counties were added: Ningcheng County, Lingnan County, Lubei County, and Tianshan County, so that Jehol Province had 20 counties and 20 flags under its jurisdiction.

From May 13 to June 25, 1937, the North China Military Region of the People's Liberation Army (PLA) launched the Battle of Jinzhecha, advancing to the western part of Jehol and the eastern part of Hebei, launching a campaign in the border areas of Hebei, Jehol, and Chahar Provinces as well as in the northern part of the Pinghan Road, in order to restrain the Kuomintang from withdrawing its troops from North China and reinforcing the Northeast.

During this period, many towns and cities were captured, and with the cooperation of the Northeastern Field Army, the Pingcheng Road and the Beining Road were cut off, forming an encirclement around Chengde. in early November, Fu Zuoyi gave up Chengde, and on November 12, the People's Liberation Army (PLA) stationed itself in the capital city of Chengde, and the administration of the ROC's Jehol government was completely dismantled.

The above reference? Baidu Encyclopedia-Rhehehe Province