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 European names that were gradually created from the habitual use of a nickname. The nicknames were given in the first instance with reference to occupation or to a variety of characteristics, such as physical attributes or peculiarities, mental and moral characteristics, supposed resemblance to an animal's or bird's appearance or disposition, and to habits of dress. In this instance the name was 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. William Sartin was christened in London in June 1636, and the marriage of Allin Sartin and Susanah Newton was recorded at St. Bartholomew the Less, also in London, on December 11th 1662. The first recorded spelling of the family name is shown to be that of William Certayn, which was dated 1394, in the "Calendar of the Letter Books of the City of London", during the reign of King Richard 11, known as "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.