This long-established surname is of Irish and Anglo-Saxon origin, and has four possible sources, each with its own history and derivation. Firstly, it may be from an Anglicized form of the Gaelic "O'Bradaigh", meaning "descendant of Bradach", a byname of uncertain etymology, thought to be connected with the Gaelic "bradach", thieving, dishonest, but this is unlikely. The prefix "Mac", denoting "son of", was usually used with the name, and the MacBradys were a powerful sept belonging to Breffny, their chief holding sway over a territory lying a few miles east of Cavan town. The earliest recorded namebearer in Ireland was Gilbert MacBrady, who was bishop of Ardagh from 1396 to 1400. The second source is from a nickname for a person with large or wide-set eyes, from the Olde English pre 7th Century "brad", broad, and "eage", eye; the earliest recording, see below, is from this source. The third origin is habitational from some place known as "broad island", derived from the Olde English "brad", broad, and "eg", island. Lastly, the name may be topographical for "a dweller by a broad enclosure", from the Olde English "brad", broad, and "(ge)haeg", enclosure. Interesting namebearers include: Phelim Brady (flourished 1710), usually referred to as "bold Phelim Brady the bard of Armagh", who was a Gaelic poet of some note; and Thomas Brady (1752 - 1827), a farmer's son from Cootehill, County Cavan, who became a Field Marshall in the Austrian service. The first recorded spelling of the family name is shown to be that of Roger Bradeie, which was dated 1170, in the "Cartulary of Oseney Abbey", Oxfordshire, during the reign of King Henry 11, known as "The Builder of Churches", 1154 - 1189. 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.