Si Maguang:the Author of "the Greatest of All Chinese Historians"

Si Maguang (司马光,1019-1086) was a Chinese historian, scholar, and high chancellor of the Song Dynasty.

Sima Guang was born in 1019 in present-day Yuncheng, Shanxi to a wealthy family, and obtained early success as a scholar and officer. When he was barely twenty, he passed the Imperial examination with the highest rank of jìnshì (进士 "metropolitan graduate"), and spent the next several years in official positions.
In 1064, Sima presented to Emperor Yingzong of Song a book of five volumes (卷), the Liniantu (历年图 "Chart of Successive Years"). It chronologically summarized events in Chinese history from 403 BCE to 959 CE, and was something like a prospectus for sponsorship of his ambitious project in historiography. These dates were chosen because 403 BCE was the beginning of the Warring States period, when the ancient State of Jin was subdivided, which eventually led to the establishment of the Qin Dynasty; and because 959 CE was the end of the Five Dynasties and Ten Kingdoms Period and the beginning of the Song Dynasty.

In 1066, he presented a more detailed 8-volume Tongzhi (通志; "Comprehensive Records"), which chronicled Chinese history from 403 BCE to 207 BCE (the end of the Qin Dynasty). The emperor issued an edict for compiling a groundbreaking universal history of China, granting full access to the imperial libraries, and allocating funds for all the costs of compilation, including research assistance by experienced historians such as Liu Ban (刘攽, 1022-88), Liu Shu (刘恕, 1032-78), and Fan Zuyu (范祖禹, 1041-98). After Yingzong died in 1067, Sima was invited to the palace to introduce his work in progress to Emperor Shenzong of Song. The new emperor not only confirmed the interest his father had shown, but proclaimed his favor by changing the title from Tongzhi ("Comprehensive Records") to the honorific Zizhi Tongjian ("Comprehensive Mirror to Aid in Government"). Scholars interpret this titular "Mirror" to mean a work of reference and guidance; indicating that Shenzong accepted Sima as his mentor in the science of history and its application to government. The emperor maintained his support for compiling this comprehensive history for decades until it was completed in 1084.

Such loyalty is notable, especially since Sima was a leader of the conservative faction at court, resolutely opposed to the reformist policies of Chancellor Wang Anshi. Sima presented increasingly critical memorials to the throne until 1070, when he refused further appointment and withdrew from court. In 1071, he took up residence in Luoyang, where he remained with an official sinecure, providing sufficient time and resources to continue compilation. Indeed, though the historian and the emperor continued to disagree on policies, Sima's enforced retirement proved essential for him to fully complete his chronological history.

Sima Guang was also a lexicographer (who perhaps edited the Jiyun), and spent decades compiling his 1066 Leipian (类篇; "Classified Chapters", cf. the Yupian) dictionary. It was based on the Shuowen Jiezi, and included 31,319 Chinese characters, many of which were coined in the Song and Tang Dynasty.
Sima Guang is best remembered for his Zizhi Tongjian masterwork, and Rafe de Crespigny describes him as "perhaps the greatest of all Chinese historians" .

There is a folktale that Sima Guang broke a great ceramic container where a boy was drowning, titled "Sima Guang Da Po Gang," which could simply be a play on his name for rhyming. He was also supposed to have created a wooden log to sleep on when he wrote the book Zizhi Tongjian so as to work more and sleep less. He called this JingJen (Alert Pillow), and used it for 19 years.