The Oera Linda Book is a 19th century manuscript written in Old Frisian. It purports to cover historical, mythological, and religious themes of remote antiquity, compiled between 2194 BC and AD 803.
The manuscript's author is not known with certainty, and it is hence unknown whether the intention was to produce a hoax, a parody or simply an exercise in poetic fantasy.
The manuscript first came to public awareness in the 1860s. In 1872, Jan Gerhardus Ottema published a Dutch translation and defended it as "genuine". Over the next few years there was a heated public controversy, but by 1879 it was universally recognized that the text was a recent composition. Nevertheless, a public controversy was revived in the context of 1930s Nazi occultism, and the book is still occasionally brought up in esotericism and "Atlantis" literature.
Goffe Jensma published a monograph on the manuscript in 2004, De gemaskerde god ("the masked god"), including a new translation and a discussion of the history of its reception. Jensma concludes that it was likely intended as a "hoax to fool some nationalist Frisians and orthodox Christians", as well as an "experiential exemplary exercise" by Dutch theologian and poet François Haverschmidt