This unusual name is of English locational origin, from the port of Tilbury on the Thames in Essex, and two other parishes also in Essex. The placename is first recorded as "Til(l)oaburg" in c. 730, and as "Tilibheria" in the Domesday Book of 1086. By 1254 it had become "Tyllebery". The derivation of the name is from the Old English pre 7th Century personal name "Tila", from "til", meaning "capable", "able", plus "burh", meaning a fortified place, a fort, often with reference to a Roman or other pre English fort. This type of locational surname was ususally that of the landholder or lord of the manor, or was a name given to former inhabitants who moved to a new location. In the modern idiom, the name can be found as "Tilbury", "Tilberry", "Tillberry" or "Tillbury". The first recorded spelling of the family name is shown to be that of Richard de Tillebyr. which was dated 1273, The Essex Pipe Rolls. during the reign of King Edward I, The Hammer of the Scots, 1272 - 1307. 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.