This rare and interesting name is of Norman French origin, introduced into England after the Conquest of 1066. As a surname, it is a good example of that large group of early names created from the habitual use of a nickname, in this instance one given to a person thought to be particularly determined or self-assured. The derivation is from the Old French term 'certeyn', sure, determined, in Middle English 'certain', from the Latin 'certanus', a derivative of 'certus', settled, sure. The development of the surname in London includes: Serten (1604), Sarten (1618), Sartaine (1619), Sarteyne (1628) and Sertayne (1642), and the modern surname can be found as Sartin, Sartain, Sarton, Sattin and Sertin. Elizabeth, daughter of John and Marie Sarten was christened on July 24th 1618 at St. Botolph without Aldgate, London. The first recorded spelling of the family name is shown to be that of William Certayn, which was dated 1394, Calendar of the Letter Books of the City of London, during the reign of King Richard 11, 'Richard of Bordeaux', 1377-1399. 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.