Who had the strongest claim to the throne?!

In the year of 1066 King Edward the Confessor of England had passed, and now there were three men, all brave and mighty, claiming to the throne. There was Harold Godwinson the leader of the English Army, who was claiming to the throne as for Edward the Confessor had promised him 2 years ago. There was Duke William of Normandy, also known as William the Conqueror, his claim being 15 years ago he visited Edward the Confessor, who then promised him as the heir to the throne. Not to mention that in 1064, Harold Godwinson was captured on a visit to Normandy, taken to William the Conqueror, and was forced to make an OATH, that promised to help William the Conqueror become the King of England. Just so you should know, making an OATH was a big deal, if you were to break an oath (promise), your life could be at steak. And then there was lastly Harald Hadrada, the Norwegian King, claimed that his ancestor was the great King of England, King Cnut. So you have learnt all their claims, but WHO HAD THE BEST CLAIM!? First of all I think that the Norwegian King is out of the picture because all he has is his mouth, he has no one to confirm that he is . I can go up to the current Queen of England and say that she is my ancestor, and then become King. NO WAY! Now it is down to Godwinson and The Conqueror. Rightfully and also known by the people Harold Godwinson is what I would believe to have a strong claim to the throne. The reason for this is because the people all knew that Edward the Confessor had promised him the throne, and also the fact that Godwinsons sister was married to Edward the Confessor it was pretty imaginable that he would become the next king and himself also being the leader of the army. I think that William the Conqueror had a strong claim but not strong enough he had no one to confirm he actually was promised to be King, or that the Oath that Godwinson made was true. But throughout all of their claims I think that Harold Godwinson had the strongest claim.