Seokbosangjeol

Seokbosangjeol (釋譜詳節) is the biography of Gautama Buddha written in Korean. It was made by Sejo of Joseon when he was still a prince. 
Sejo of Joseon used Chinese books as source text for the book. It features books like Lotus Sutra, Kṣitigarbha Bodhisattva Pūrvapraṇidhāna Sūtra, and Amitabha Sutra. It was the first time that someone had translated Buddhist sutras into Korean language from Chinese language. The book was made after Sejo of Joseon's mother died. People from around Korea were able to buy the book. It was published in 1447. It came in 24 volumes. Many of the volumes have been lost. The National Library of Korea owns a copy.
The book is one of the first times that the "hangul" alphabet was ever printed in a book.