There is an interesting article about this man in the "Maryland Magazine of Genealogy," Vol. 4, #2, Fall, 1981, written by George Ely Russell.
"William Vanhaesdunk Riddlesden was sentenced to death in England but was soon pardoned on the condition that he be transported to the American colonies for seven years."
He returned to England, was caught, and again sentenced to be sent to America, where he continued his criminal activities."His modus operandi was to forge documents pretending ownership to various large tracts of land, to impersonate William Cornallis, heir to Mr. Thomas Cornwallis, an original adventurer to Maryland in 1634, and to sell thge tracts to various unsuspecting people.....It is known he sold land in the Eastern Shore counties of Cecil, Queen Anne's, Talbot, and Dorchester."
About 1725 "Riddlesden was no longer living within the jurisdiction of Maryland.His wife, Sarah Herbert had presumable died and he had married Rebecca Fisher, relict of Yeates Conwell of Sussex County, Delaware, and was living under the assumed name of William Cornwallis.Their marriage occurred before 8 August 1727, on which date Rebecca Cornwallis, wife of William Cornwallis, formerly known as Rebecca Conwell, administered the estate of her late brother Elias Fisher, Get., who died intestate in Sussex County."
"The will of William Cornwallis of Sussex County (Delaware) was dated 24 March 1727/8, and mentioned wife Rebecca and step children, John, William, Benjamin, and Hannah Conwell."