The Chinese kept consistent and accurate court records after the year 841 BC, with the beginning of the Gonghe Regency of the Western Zhou Dynasty. The earliest known narrative history of China was the "Zuo Zhuan", which was compiled no later than 389 BC, and attributed to the blind 5th-century BC historian Zuo Qiuming. The "Book of Documents" is thought to have been compiled as far back as the 6th century BC, and was certainly compiled by the 4th century BC, the latest date for the writing of the Guodian Chu Slips unearthed in a Hubei tomb in 1993. The "Book of Documents" included early information on geography in the "Yu Gong" chapter. The "Bamboo Annals" found in 281 AD in the tomb of the King of Wei, who was interred in 296 BC, provide another example; however, unlike the "Zuo Zhuan", the authenticity of the early date of the "Bamboo Annals" is in doubt. Another early text was the political strategy book of the "Zhan Guo Ce", compiled between the 3rd and 1st centuries BC, with partial amounts of the text found amongst the 2nd century BC tomb site at Mawangdui. The oldest extant dictionary in China is the "Erya", dated to the 3rd century BC, anonymously written but with later commentary by the historian Guo Pu (276–324). Other early dictionaries include the "Fangyan" by Yang Xiong (53 BC – 18 AD) and the "Shuowen Jiezi" by Xu Shen (58–147 AD). One of the largest was the "Kangxi Dictionary" compiled by 1716 under the auspices of the Kangxi Emperor (r. 1661–1722); it provides definitions for over 47,000 characters.