The Wanradt–Koell Catechism (Estonian: Wanradti ja Koelli katekismus) is a partly preserved book that is considered the oldest printed source of Estonian. The oldest known examples of handwritten Estonian appear in 13th-century chronicles. The book was compiled by the clergymen Simon Wanradt [de] and Johann Koell [de]. The book was published in 1535 in Wittenberg.[1]
Fragments from the book were discovered in 1929 by the historian Hellmuth Weiss.[1]