Chahar (Mongolian: ᠴᠠᠬᠠᠷ; traditional Chinese: 察哈爾; simplified Chinese: 察哈尔; pinyin: Cháhā'ěr), also known as Chaha'er, Chakhar, or Qahar, was a province of the Republic of China in existence from 1912 to 1936, mostly covering territory in what is part of eastern Inner Mongolia.