Pingding Chaha'er fanglüe 平定察哈爾方略 "Miliary annals of the pacification of the Chahar" is a history of the submission of the Eastern Mongols (Chaha'er, Tsakhar, Čaqar) by the Qing dynasty 清 (1644-1911). It was compiled on imperial order by the Military Archive (fanglüeguan 方略館) but was never published. It is recorded in Tao Xiang's 陶湘 (1871-1940) catalogue Gugong dianben shuku xiancun mu 故宮殿本書庫現存目 "Bibliography of preserved books of the libaries in the Imperial Palace", but was for a long time thought lost. Only in 1964, it was rediscovered in the Ming-Qing archives. The Archival Department of the Renmin University (Renmin Daxue Dang'anxi 人民大學檔案系) confirmed the authenticity of the finding. There are a Chinese version and a Manchu version. It was then transferred to the Library of the Central Academy of Ethnology (Zhongyang Mingzu Xueyuan Tushuguan 中央民族學院圖書館) and published in the series Minzu guji congshu 民族古籍叢書.
In the publication in the periodical Qingshi yanjiu tongxun 清史研究通訊, a compiler called Ledehung 勒德洪 is mentioned, of which not much is known. According to the book Qingdai zhiguan nianbiao 清代職官年表, a table of high officials of the Qing, he was vice minister of the Ministry of Justice (xingbu zuo shilang 刑部右侍郎), and later became Minister of Revenue (hubu shangshu 戶部尚書). He was then transferred to a post as Grand Academician (daxueshi 大學士) in the Wuying Hall 武英殿. He is also mentioned as one of the compilers of the Pingding sanni fanglüe 平定三逆方略.
The book Pingding Chahar fanglüe gives an overview of the increasing power of the Chahar tribe of the Eastern Mongols under Ligdan Khan 林丹 (Liγdan Qaγan). It was during the reign of Hung Tayiǰi (r. 1626-1643) that the Manchus undertook a first campaign against Ligdan and appeased the Mongol Khan by marrying a princess to him and giving him the title of an imperial prince (qinwang 親王). When Ligdan was still refraining from exhibiting his obedience, he was stripped off his ranks, and his son Burni 布爾尼 was invested. The Kangxi Emperor 康熙帝 (r. 1662-1722) then dispatched a large army to crush the resistance of Ligdan, also with the help of other Mongol allies, the Khalkha. The forces of Burni and Lobzang 羅布臧 (Lubcang tayiǰi Erinčin) were defeated, Burni's father Abunai 阿布奈 was killed, and their troops surrendered. The pacification of the Chahar Mongols was an important step for the Manchus to have a free back for the war against Wu Sangui 吳三桂 (1608-1678), the rebel in southern China.