bishop james ussher
In case you've missed it, the good bishop has gone to history as the man responsible for dating the biblical creation. However, I think that the poor man would be horrified if he knew that that was what he would one day become famous for.

While I rather like my grandfather's suggestion that the dating itself was a joke at the expense of the uneducated masses, created by an educated and highly intelligent man who had tired of parishioners asking the question, I am more inclined to agree with the late Stephen Jay Gould that Bishop Ussher's calculations were state of the art at the time. I am quite sure that if he were alive today he would fully agree with the current scientific consensus. In his own time he was a respected scholar as well as an effective leader and administrator, so much so that he was given a state funeral and buried at Westminster Abbey.