This most interesting and intriguing surname is a late variant of "Somerled, Summerlad" itself the Anglicized form of the Gaelic personal name "Somhairle", which is the Gaelicized version of the Old Norse personal name "Sumarliethi", composed of the elements "sumar", summer and "liethr", warrior, hence a summer warrior, viking pirate, mariner. The Old Norse personal name was originally not a personal name, but signified a viking who used to come to Britain in the summer; the Pictish Chronicle, for instance, speaks of "the fleets of the Somerleds". Sumerled, first of the name recorded in Scotland, witnessed a confirmation of the Church of the Holy Trinity of Dunkeld to the Abbey of Dunfermline in 1169. Sumerleith de Fetherhesan was juror in a dispute regarding the Kirketun of Aberbuthenoth in 1206. The name may also be found with the Gaelic prefix "Mac", "son of", and was first recorded much earlier than Sorley in 1355, when Alexander M'Sommarrli gave evidence in Argyllshire. Ronald McSoirlie was charged with holding the castle of Dunivaig against Bishop Knox in 1616. MacSorley is also found in Ulster, where it is of Scottish origin, coming across in the 13th Century with gallowglass invaders. Elizabeth, daughter of John Sorley, was christened in December 1607 at St. Margaret's, Westminster, London. The first recorded spelling of the family name is shown to be that of John Soirlie, which was dated 1590, in the "Scottish Antiquary Records", during the reign of King James V1 of Great Britain (1567 - 1625). 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.