This ancient name is of Anglo-Saxon origin, and has the unusual distinction of being first recorded some seventy years before the Domesday Book of 1086. As a surname, Bygrave may be either locational or topographical in origin; if the former, it derives from the place called Bygrave near Baldock in Hertfordshire, which is recorded as "Bigrafan" in the Saxon Chartulary of 973, and as "Bigrave" in Domesday. The place is so called from the Olde English pre 7th Century "bi Grafan", (the place) by the ditch, from "grafa", ditch, a derivative of "grafan", to dig; in Middle English this became Bygrave. As a topographical surname, Bygrave denoted residence by a ditch or dike, probably dug for defensive purposes. Locational surnames were used particularly as a means of identification by those who left their birthplace to settle elsewhere, and topographical features in the landscape provided convenient distinguishing names in the small communities of the Middle Ages. One William Bygrave is listed in the Calendar of Letter Books of the City of London in 1312, and early recordings from Church Registers include those of the marriage of Edmund Bygrave and Elizabeth Hitchen in Great Wymondley, Hertfordshire, on October 20th 1571, and of Robert Bygrave and Jone Prentise at St. Margaret's, Westminster, London, on April 21st 1577. The first recorded spelling of the family name is shown to be that of Leommaer (aet) Biggrafan, which was dated circa 1015, in "Anglo-Saxon Wills of Hertfordshire", during the reign of Ethelred, known as "the Unready", King of England, 978 - 1016. 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.