When historians all independently come to the same conclusion

That is very true, Keith. When you have read what all historians say and can confirm that they all come to the same conclusion I may be more inclined to agree. But what you are saying is that all historians that you have read come to the same conclusion. All historians is not synonymous with all historians that you have read. I am not disagreeing with you about your points but let us not go round that circle again. Until you can, hand on heart, say that every historian in the world agrees with you, there will always be an element of doubt.