This interesting name is of early medieval English origin, and is primarily a nickname surname from the use of the Olde English pre 7th Century word "saelig", a derivative of "sael", meaning happiness, good fortune, used as a term to describe someone with a cheerful, happy disposition. The Middle English development was to "seely", meaning happy, fortunate, which became a surname as early as the 13th Century (see below). Occasionally, the word was used as a female personal name during the Middle Ages, recorded as "Sela" in 1219, and as "Sely" in 1221, and this may have been the source for some bearers of the modern surname, which has at least seventeen variant forms, ranging from, Seal(l)y, Seel(e)y and Sill(e)y, to Ceel(e)y and Zeal(e)y. The sense of "pitiable", which developed into the modern English "silly", is a later 15th Century usage. On October 3rd 1566, Isaak, son of Nicholas Seeley, was christened at Holy Trinity in the Minories, London, and William Seely, aged 29 yrs., was an early settler in the New World Colonies, leaving London on the "Alexander", bound for the Barbadoes in May 1635. A notable namebearer was Sir John Robert Seeley (1834 - 1895), who was chief classical assistant at the City of London School in 1859, and was professor of modern history at Cambridge from 1869 - 1895. The first recorded spelling of the family name is shown to be that of Richard Seli, which was dated circa 1200, in the "Gilbertine Charters of London", during the reign of King John, known as "Lackland", 1199 - 1216. 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.