Recorded in many spellings including Gallop, Gollop, Yallop, Yollop, Jollip, Gillop, Gillup and others, this very interesting surname is almost certainly English. It appears to be locational and to derive from a "lost" medieval village. As some three thousand surnames are known to originate from now lost sites in the British Isles, this is unusual, but by no means unique. Most of these villages disappeared between the 16th and the 18th centuries as landlords were able to legally repossess common lands, and thereby to derive the tenants of their ancient grazing. This forced them to leave the land and to move to the growing cities. In addition as the cities grew they also swallowed up villages, a practice which continues into the 20th century and shows few signs of stopping. In this case we believe that the placename and hence the later surname, may derive from pre 7th century Olde English personal name 'Ealda' and 'op' meaning a hill top. As to where this place is, we are uncertain, although the county of Somerset has been suggested. Early examples of the surname recording taken from surviving church registers of Greater London include Barabara Yelpe who married John Forest at St Pancras Old Church on September 14th 1550, Robert Yollop who married Dorothy Spelman at St Gregory's by St Pauls Cathedral, on July 21st 1657, Robert Gillup at St Dunstans in the East, Stepney, on April 12th 1663, Ann Gallop who married Henry Bankes at the same church on December 27th 1664, and Mary Yallop who married Charles White at St James Clerkenwell, on April 5th 1662.