This is the Irish and specifically Ulster form of the (now) Scottish surname Chrystal, Crystal, and Christal. Curiously the Scottish form does not have, nor does it ever seem to have had, the definitive prefix 'Mac' meaning son of. The name in all its spellings has the same origin, being a diminutive spelling of the Norman 'Christopher', and as such introduced into Britain after the 1066 Invasion of England. The name is of Ancient Greek origins and the 20th century translation is 'Christ bearing', which can hardly have been its original meaning. The name is first recorded in Scotland in the mid 15th century, when William Christole was recorded as being a 'burgess of Prestwick', whilst in 1474 one Charles Christoll was recorded as being presented in court in order to ascertain whether he was the 'narrest and apperand arr to Cristole Jonsoun'. Whether he was or not is not recorded! The later Irish recordings include Henry McCrystal of Clogher, County Tyrone, on June 1st 1844, and Bridget McCrystal aged twenty, a passenger on the ship Adirondack, which originally sailed from Liverpool to New York on September 1st 1846, calling at Belfast Lough. This was a 'coffin' ship, chartered to carry people fleeing the worst effects of the Irish 'Potato Famine' of 1846/47. The first recorded spelling of the family name is shown to be that of Roger Christofore, which was dated 1379, in the Poll Tax Rolls of the county of Yorkshire, England, during the reign of King Richard 11, known as 'Richard of Carnafon', 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.