The surname of ALLSWORTH and its variant ELLSWORTH were derived from the Old English 'Eallsworp', a Cheshire surname. The first instance of the name was Alevrde, listed as a tenant in the Domesday Book of 1086. In 1086 the compilation of the Domesday Book was ordered by William the Conqueror (1027-87), king of England from 1066. He was born in Failaise, the bastard son of Robert, Duke of Normandy, by Arlette, a tanner's daughter. On his father's death in 1035, the nobles accepted him as a duke. When Edward the Confessor, King of England died in 1066, William invaded England that Autumn, on 14th October, 1066 killing Harold (who had assumed the title of King). English government under William assumed a more feudal aspect, the King's tenants-in-chief and all title to land was derived from his grants, and the Domesday Book contains details of the land settlements, and the names of the owners of such. Early records of the name mention Allewrdth of the County of Cheshire in 1182. Siward de Alsweth was a charter witness in 1200, Scotland. Richard Alworthe was listed in the Yorkshire Poll Tax of 1379. The name is also spelt as Alworth and Allworthe. When the coast of England was invaded by William The Conqueror in the year 1066, the Normans brought with them a store of French personal names, which soon, more or less, entirely replaced the traditional more varied Old English personal names, at least among the upper and middle classes. A century of so later, given names of the principal saints of the Christian church began to be used. It is from these two types of given name that the majority of the English patronymic surnames are derived and used to this day.

The associated coat of arms is recorded in Sir Bernard Burkes General Armory. Ulster King of Arms in 1884. Registered in Devonshire.