Joseon Wangjo Sillok comprises of 1,893 books and 888 volumes covering 472 years (1392-1863) of the history of the Joseon Dynasty in a chronological order, from the reign of King Taejo, the founder, to the end of the reign of King Cheoljong. The contents of these annals are encyclopedic, including general state affairs, economy, culture and politics. They are also highly reliable records with historic authenticity and credibility. Historiographers were legally guaranteed independence in their record keeping and the right to keep secrets. After a king's death and the coronation of his successor, professional officials were appointed to write the annals of his reign at the Sillokcheong, the Office for Annals Compilation. Nobody was allowed to read the sacho, or draft history, not even the king. Once the annals were compiled in multiple copies, each copy was stored in special archives. Up until the early 20th century, most of the copies stored at archives in Taebaeksan Mountain, Jeongjoksan Mountain, Jeoksangsan Mountain and Odaesan Mountain survived, even after the massive destruction by the Japanese Invasion (1592-1598) and the Qing Invasion (1636-1637). This edition comprised 558 scattered pages covering the period from the reigns of King Jeongjong to Gwanghaegun. These pages were stored unattended at Kyujanggak Institute for Korean Studies for a long time, but in June 1972, they were compiled into 21 volumes by Seoul National University Library.