Various Sources for the Allen/Allan/Allyn/Allin Name Meaning

English and Scottish: from a Celtic personal name of great antiquity and obscurity. In England the personal name is now usually spelled Alan, the surname Allen; in Scotland the surname is more often Allan. Various suggestions have been put forward regarding its origin; the most plausible is that it originally meant ‘little rock’. Compare Gaelic ailín, diminutive of ail ‘rock’. The present-day frequency of the surname Allen in England and Ireland is partly accounted for by the popularity of the personal name among Breton followers of William the Conqueror, by whom it was imported first to Britain and then to Ireland. St. Alan(us) was a 5th-century bishop of Quimper, who was a cult figure in medieval Brittany. Another St. Al(l)an was a Cornish or Breton saint of the 6th century, to whom a church in Cornwall is dedicated.

http://www.ancestry.com/name-origin?surname=allen

Allen is a surname of English, Scottish and Irish origin, coming from aluinn meaning 'fair' or 'handsome'.[1] Allen is the 42nd most common surname in the United Kingdom.[2] It is reported as 27th in a list of common surnames in the United States.[3] In Ireland, Allen is the Anglicization of the Gaelic name Ó h-Ailín

http://en.wikipedia.org/wiki/Allen_%28name%29

Allen

  This distinguished surname with more than fifty heraldic Coats of Arms granted to nameholders, and having several notable entries in the British 'Dictionary of National Biography', is equally widespread in England, Scotland and Ireland. It derives from the Gaelic and Breton personal name of the pre-Christian era 'Ailin' which loosely translates as 'Little rock, although it may also mean 'harmony'. The first recorded name bearer was 'Alawn', a legendary poet of the fifth century a.d., reputed to be one of the three foremost musicians of the period. From early times the spelling form has varied considerably not least in the Celtic countries where it has ranged from Eilian to Alwyn and Alleyne. The Bretons, who were originally British settlers in France, returned as invaders with William, Duke of Normandy, otherwise known as 'The Conqueror' in 1066, and in so doing it is claimed, re-introduced the name into England. Certainly 'Alanus' without a surname, is recorded in the 1086 Domesday Book for the county of Suffolk. Early surname recordings include those of Roger Alain of Yorkshire in the rolls of the village of Calverly, in 1246, and Richard Aleyns of Staffordshire, in the Assize Court Rolls of 1309. Other examples are John Allen, prebendary of St Pauls Cathedral, London in 1527, whilst in 1638 another John Allen was a puritan divine, and one of the earliest settlers in the New England colonial city of Plymouth, USA. The coat of arms most associated with the surname has the blazon of a gold field, charged with three black hounds passant, the crest being an eagle rising. The first recorded spelling of the family name is shown to be that of Geoffrey Alein, which was dated 1234, in the 'Feet of Fines' rolls of Cambridgeshire, during the reign of King Henry 111, known as 'The Frenchman', 1216 - 1272. 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.

http://www.surnamedb.com/Surname/Allen

ALLEN Surname Meaning & Origin:

The Allen and Allan surname derives from "aluinn," meaning fair or handsome.

The Allan surname spelled with an "a" is generally considered to be associated with Scottish clans, including Clan Donald, Clan Grant, Clan MacFarlane and Clan MacKay. Spelled with an "e," however, the Allen surname is generally considered to be English in origin. However, a variety of names from a variety of regions might be anglicised as either Allen or Allan, so the name spelling may not point to your family's origin.

http://genealogy.about.com/od/surname_meaning/p/allen.htm