Origin of the Name Brennan
family history was found in the allfamilycrests.com archives.
Over the centuries Surnames developed a wide number of variants. Different spellings of the same name can be traced back to an original root. Additionally when a bearer of a name emigrated it was not uncommon that their original name would be incorrectly transcribed in the record books at their new location. Surnames were also often altered over the years based on how they sounded phonetically and depending on the prevailing political conditions it may have been advantageous to change a name from one language to another.Variants of the name Brennan
include Brannon, Brannan and Brennand. These names are derived from the Gaelic O'Braonain septs whose Gaelic name taken from the Gaelic word 'braon' which has a number of meanings including 'sorrow'. The principal sept of O'Brennan was of Ossory where they were Chiefs of Ui Duach in Northern Kilkenny. In the face of the twelfth century invasion the sept's power waned and by the seventeenth century many of sept were reduced to the status of Rapparee. Another quite different sept was in the Eastern part of County Roscommon, whose Chief was MacBranain. Most of the Chiefs who appear in the Annals between 1159 and 1488 retained the 'Mac' until the submergence of the Gaelic order, when the 'O' prefix began to appear. The County Fermanagh sept of O'Branain also anglicized their name as Brennan as well as Brannan. A fourth sept was located in County Kerry from where their descendants spread to County Cork.
The Brennan coat of arms came into existence centuries ago. The process of creating coats of arms (also often called family crests) began in the eleventh century although a form of Proto-Heraldry may have existed in some countries prior to this. The new art of Heraldry made it possible for families and even individual family members to have their very own coat of arms, including all Brennan descendants.