This is a patronymic "the son of Dumphy" - a petform of the Olde French personal name Humfrey (now spelt Humphrey). The name was introduced into England by the Normans and is recorded in the Domesday Book of 1086 as Hunfridus and Humfridus. The name bearers most likely being followers of William the Conqueror who had been granted lands. The name means bear (hun) and peace (frid). In the modern idiom the name is spelt Dumphy, Dunphy and Dunphie with the forms Dumphrey, Dumphries and Dumphry being synonyms. All the pet forms with the initial "D" are, no doubt, rhymed on Humphrey as in "Humpty-Dumpty..." The first recorded spelling of the family name is shown to be that of Mr Dumphrey (a working man) which was dated 1886, in the "Standard" during the reign of Queen Victoria, known as "The Great White Queen" 1837 - 1901 Surnames became necessary when governments introduced personal taxation. In England this was known as Poll Tax. Throughout the centuries, surnames in every country have continued to "develop" often leading to astonishing variants of the original spelling.