In 1164, St Olaf was recognised as an official Catholic saint by Pope Alexander III. Churches Dedicated to St OlafThe cult of St Olaf spread rapidly throughout northern Europe during the Middle Ages. In English, his name is variously spelt Olaf, Olav, or Olave, and there are many churches dedicated to St Olaf, St Olav, or St Olave across the British Isles where there are links with the Vikings. Beyond Norway, St Olaf's Day is marked in places with Scandinavian heritage and by churches dedicated to St Olaf (also spelt St Olav or St Olave). HeimskringlaThe stories of St Olaf and other Scandinavian kings were written in Norse sagas, which were collected together as the Heimskringla.