The database for "Seungjeongwon Ilgi," the world's largest historic recordings written in the Joseon Dynasty (1392-1897), has been completed after 15 years of documentation and proofreading, the national history institution said Thursday.

Dozens of historians had been mobilized per year for the highly specialized process started in 2001, which is also when the recordings were listed as a UNESCO documentary heritage, the National Institute of Korean History said.

"Seungjengwon Ilgi," also known as the Diaries of the Royal Secretariat, records the king's daily life starting from the beginning of the Joseon era.

Only about half the contents, however, remain today, spanning more than 240 million characters and covering kings from the 17th century to the early 20th century.

The institute's website will be updated by the end of next month to list all 141 volumes of the diaries. But interpretation of the recordings is expected to take another decade, if not longer, the institute said. (Yonhap)