Recorded as MacKissack, MacKessack, MacKessock, MacKissek, and the short forms commencing Mc, and sometimes without a prefix at all as in Kissack and Kissock, this is a Scottish surname. It originates from the Gaelic name Mac Iosaig, meaning the son of Isaac. This is almost certainly a 'Crusader' name of biblical origins, which was brought back from the Holy Land in the 11th or 12th centuries by returning Knight Templar's or other pilgrims. Like many names of Hebrew origins, as a surname in the British Isles Isaac was Christian and not Jewish. Such holders of the name who are Jewish are relatively recent settlers in the British Isles. It is unclear when the surname was first recorded but Molmoria M'Kesek appears as a landowner in the barony of Glastry in 1476, and it is said that a sept of the clan live on the Moray Firth and have done since the 15th century. Other recordings include that John M'Inthir (MacIntyre?) who in 1623 was sentenced to death for allowing quote 'M'Keissak's bairns die for hunger'. In 1745 Duncan M'Kissoch is recorded as being a Jacobite, who was taken prisoner after the battle of Culloden. His fate is not known, but most who escaped the field were later transported for life to Nova Scotia in Canada.