One such error was made when the English barony of Wharton was conferred upon a claimant, believing that the barony had been created by writ of summons; however, the original barony had been created by letters patent to the heirs male of the original grantee. In this case, the original documentation had been lost.
Similar errors were made for the Percy barony when the 2nd Duke of Northumberland was summoned to Parliament erroneously in 1722 as Baron Percy (in the belief that the 1299 barony had descended to his mother), and the Strange barony created in 1628 for the 7th Earl of Derby by error.
Since the early twentieth century, the Committee on Privileges has been reluctant to revive older English baronies on various grounds, and thus, the opportunity for new baronies to be created by clerical error or failure in research are rare.
The most common errors are made in the spelling of a title as granted in letters patent.
This category does not include baronies such as the very old English Barony de Ros or the Barony of Hastings that were awarded to persons who were not the senior heir (or co-heir) general. Nor does it include baronies that were not awarded at all to the claimant, for various other reasons.