And example of where historians do disagree because of the varied reliability of the contemporary sources is the Battle of Brunanburh. There is general agreement on who the protagonists were, and that there was great slaughter, and that in some sense Aethelstan "won". But what there is no agreement on is the site of the battle, and this is because the main documentary source, the Anglo-Saxon chronicle, is silent on the issue. Now there will be articles in scholarly journals from historians proposing, providing evidence for and against, various sites. And that evidence will be weighed up, but none of those historians will say that they have the definite answer. This is scholarly debate, not disagreement, it is part of the process by which facts are established, and in this case the prime fact has not yet been established.