The 25 Official Dynastic Histories 二十五史 (www.chinaknowledge.de)

http://www.chinaknowledge.de/Literature/Historiography/ershiwushi.html

The 25 Official Dynastic Histories (Ershiwu shi 二十五史), called orthodox histories (zhengshi 正史), are a subcategory of the category of historiography in traditional Chinese bibliography.