This interesting surname has a number of possible sources. Firstly, the surname may be a Cornish and Welsh locational name from any of the places thus called, for example: Glyn Dyffryn, near Corwen, Merioneth; Glynn, south-east of Carmarthen; Glynn, south-west of Llandilo, Carmarthenshire; and Glynn, on the river Fowey, in east Cornwall. The placenames derive from the Cornish "glin", Welsh "glyn", valley. Locational surnames were developed when former inhabitants of a place moved to another area, usually to seek work, and were best identified by the name of their birthplace. The surname may also be of Scottish origin, and is a topographical name for someone who lived in a valley, from the Gaelic "gleann", valley, or a locational name from a place named with this word, such as Glen near Peebles. Finally, the surname may be of Irish origin, and is an Anglicized form of the Gaelic "Mag Fhloinn", son of the ruddy one (from "flann", ruddy). The main sept of "Mag Fhloinn" originated in the Westmeath-Roscommon area, whence they spread west of the Shannon, mainly to Sligo and Clare, and even as far north as Donegal. One Rev. Martin Glynn (1729 - 1794), going from the diocese of Tuam to France, became superior to the Irish College at Bordeaux, of which he was the last rector, and was guillotined during the French Revolution. The first recorded spelling of the family name is shown to be that of Colban del Glen, who received a legacy left him by the Queen, which was dated 1328, in the "Exchequer Rolls of Scotland", during the reign of King Robert 1 of Scotland, 1306 - 1329. 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.