This unusual surname is of Old French origin, and derives from either of two Germanic male given names, Bertaud or Bert(h)ier, both having "berht", bright, famous, as their initial element, with "wa(l)d", ruler, and "heri, hari", army, as their respective second elements. Pre 7th Century Anglo-Saxon and Norse baptismal names were usually distinctive compounds whose elements were often associated with the Gods of Fire, Water, and War. The popularity of the above names gave rise to a variety of diminutive and pet forms including: Bertelin, Berthelin, Bertelet, Bertelot and Berteron. In the Tallage Rolls of Paris, dated 1292, the same person is entered as "Bertaut" and "Bertelot". It was the Normans who initially introduced the name into England after the Conquest of 1066 (see below for first recording). Entries in French Church Registers include the birth of Bonaventure, son of Nicolas Bertheline and Jeanne Bejard, at Troyes, Aube, on February 2nd 1611, and the christening of Pierre Bertelin, an infant, at Angers, Maine-et-Loire, on April 7th 1635. On October 1st 1820, Henry Bertlin was christened at St. Giles, Camberwell, London. A Coat of Arms granted to the Berthelin family of Poitou, Champagne, depicts a gold leopard's head, langued red, on an azure shield surrounded by a gold bordure. The first recorded spelling of the family name is shown to be that of Godricus Bertelot, which was dated circa 1157, in "Records of St. Benet of Holme", Norfolk, during the reign of King Henry 11, known as "The Builder of Churches", 1154 - 1189. 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.