This very rare and interesting name is of early medieval English origin, from a female personal name found recorded in England from the 13th Century on, spelt variously Ysemay, Isemay, Ysmay and Isamaya. The given name is thought to derive from an Old German compound name, 'Ismagi(n)', translating as 'iron-strength', and also forming the origin of another female personal name, Ismena or Ismenia. 'Ismay' is the only surname to derive from the given name Ismay, although Ismenia has been the origin for many variant surnames, such as Emeney, Emmence, Emans and Immink. The marriage of one Alyce Esmay and Henry Hamon was recorded on October 29th 1568 at St. Giles, Cripplegate, in London, and John Ismay married Elizabeth Martin at St. Margaret's, Westminster, on October 14th 1656. The first recorded spelling of the family name is shown to be that of Ralph Isemay or Hyssmaye, which was dated circa 1200, Charters of Sheffield, Yorkshire, 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.