This name is of Scottish locational origin from a place thus called in the former county of Morays (now part of the Grampian region). Recorded in the 13th century as Brennath, the name is believed to derive from the Gaelic 'broanach' meaning a damp or misty place. The final element 'ath' may also, mean a 'ford'. The surname is first recorded in the latter half of the 13th century (see below). One Andrew de (of) Brenach was clerk to Sir Dovenald Earl of Mar in 1291 - 'Calendar of Documents' at Edinburgh and a Walter de Branach was chaplain to the King at Moray (1360). The spelling de Byrneth appears in Moray (1463). The form Birnie is well recorded in Edinburgh Church Registers from the mid 17th century on. The marriage of one Elizabeth Birnie and John Smyth took place on October 5th 1652. The first recorded spelling of the family name is shown to be that of James de Brennath, burgess of Elgin, who was on an inquest concerning the King's garden there. which was dated 1261 'The Acts of the Parliaments of Scotland'. during the reign of Alexander III of Scotland 1249-1286. 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.