"John Thornburgh of Hamsfeld, esquire, married Elizabeth daughter of Sir Henry Pierpoint knight. They had issue, William, Thomas, John dean of York, and Margaret married to William Easton of the county of Lancaster."
There was a John Thornborough (of Salisbury) who was Dean of York 1589-1617, much too late to be of this generation. The note in the pedigree appears to conceived from vanity.
