Geoffrey of Monmouth was a 12th-century British cleric and historian. He is thought to have come from Monmouth in Wales and was active in Oxford.
His History of the Kings of Britain, written around 1136, tells the history of the kings of Britain and helped spread the stories of King Arthur and the wizard Merlin across Europe. In it, he wrote that Stonehenge was built by Merlin, who used magic to carry the giant stones from Ireland. Although much of it is fanciful as history, it had a great influence on later literature.
