Derived either from the Olde English 'seap' and meaning 'the dweller by the pool' or from the Medieval Gaelic 'siteach' and meaning 'the one who dwells at the eyrie'. In the second case the name is spelt as Sheehy, Sheekey, Sheach, Shiach, Seath and Seth and the name holders claim descent from the McDonnels of Scotland although they have been in Ireland since 1400 and were renowned for their fighting qualities. There is also a variant of the Hebrew Seith and introduced by the Crusaders. The first recorded spelling of the family name is shown to be that of William atte Seth. which was dated 1275, The Pipe Rolls of Worcester. during the reign of King Edward 1 The Hammer of the Scots 1272 - 1307. 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.