Sima Guang (1019 - 1086) was a statesman and historian of Northern Song Dynasty. He was born in Xiaxian county, Shan Prefecture (belong to Shanxi province today) and he was born in an official family. He served as a prime minister at one time.

The most extraordinary achievement of Sima Guang was compiling the Comprehensive Mirror for Aid in Government. Sima Guang was convinced that those governing the country should be well versed in history. He spent two years in writing a history book including the history from the Warring States Period to the end of Qin Dynasty, which was called General History. Later, when he submitted the book to Emperor Yingzong of Song Dynasty, the Emperor was satisfied and encouraged him to continue to compile the book. Emeror Yingzong allowed Sima Guang to choose the compiling crew by himself and read the collected books of the library. Sima Guang was so delighted that he set up a press immediately and invited many famous historians of that time to be his assistants, and began to compile the general history together. They collected a lot of materials, many of which had never been recorded in other history books, making them very precious.

It took Sima Guang's painstaking effort to compile this book. He was afraid too much sleep would delay the work, so he ordered a pillow made of a round log. If he turned over during sleep, the pillow would slip from his head and he would wake up. This pillow was called the "alarm pillow".

Sima Guang spent a totla of 19 years on this book. The succeeded Emperor Shenzong of Song Dynasty thought highly of the book and named it Comprehensive Mirror for Aid in Government. The book is a comprehensive history of China in chronological style covering 1,362 years from 403 BC to 959 AD. This magnum opus comprises 294 volumes containing more than 3,000,000 words. The material was very detailed, and the words were exquisite and fluent. This book became the model for later chronicle history books, and is a precious cultural inheritance of ancient China.