The history of Christianity in Norway started in the Viking Age in the 9th century. Trade, plundering raids, and travel brought the Norsemen into close contacts with Christian communities, but their conversion only started after powerful chieftains decided to receive baptism during their stay in England or Normandy. Haakon the Good was the first king to make efforts to convert the whole country, but the rebellious pagan chieftains forced him to apostatize. Olaf Tryggvason started the destruction of pagan cult sites in the late 10th century, but only Olaf Haraldsson achieved the official adaption of Christianity in the 1020s. Missionary bishops subjected to the archbishops of Hamburg-Bremen were responsible for the spread of the new faith before the earliest bishoprics were established around 1100.