Al-Idrisi's full 12th-century world map, with Britain at the bottom right; al-Idrisi seems to have possessed reasonably detailed information about the south and east coasts of Britain, see http://www.caitlingreen.org/2016/03/al-idrisi-twelfth-century-map.html … & http://www.caitlingreen.org/2016/04/islamic-gold-dinars-anglo-norman.html … (image: https://upload.wikimedia.org/wikipedia/commons/archive/a/a1/20141217140029%21TabulaRogeriana_upside-down.jpg …)pic.twitter.com/90fLCCFrt5