Recorded in several forms as shown below, this is an Irish surname. It derives from the Gaelic O' Tighearnaigh, meaning the grandson or male descendant of Tighearnach, the latter translating as lord or master. Traditionally Irish family names are taken from the heads of tribes, revered elders, or from some illustrious warrior, and are usually prefixed by O' or Mac, denoting "son of". This surname is especially widespread in County Galway, whereas the earliest recording is found in County Limerick in the early 18th Century (see below). In the modern idiom the surname can be found recorded as Tierney, Tierny,Tiernaney, O'Tierney, Tearny, Tearney and Terney. Recordings from various church registers include the christening of James Tierny, on June 4th 1741, at Limerick Cathedral, County Limerick; the christening of Penelope Tierney on April 17th 1754, at St. Olave's, Hart Street, London; and Patrick Tiernaney who left Liverpool bound for New York on the ship Marmion on May 18th 1847. The family coat of arms has the blazon of a silver shield charged with a red chief and overall a black chevron. The crest is an oak tree. The first recorded spelling of the family name is shown to be that of John Tierny, which was dated 1735, when he married Ann Young, at Limerick Cathedral, County Limerick. Surnames became necessary when governments introduced personal taxation. In England this was sometimes known as the Poll Tax. Throughout the centuries, surnames in every country have continued to "develop" often leading to astonishing variants of the original spelling.