The Oera Linda Book is a manuscript written in Old Frisian. It purports to cover historical, mythological, and religious themes of remote antiquity between 2194 BCE and 803 CE. 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. 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