This interesting name, with spellings MacNair, MacNayer, Macneir, Macnuir and MacNuyer, and the short spellings commencing Mc, is Scottish and sometimes Irish. It is considered to have four origins. Firstly, it may be derived from the pre 10th century Gaelic Mac Iain Uidhir, translating as " The son of sallow John", through the form Mac-an-uidir, and later condensed into M' In-nir; hence, Macnair. The Macnairs of Rossshire derive their name from this source. The Perthshire nameholders are a branch of the MacNabs, and explain their name as "son of the heir", from "Mac an Oighre". Perthshire documents record the surname as MacNayre in 1370. Thirdly the Gaelic Mac an fhuibhir, meaning the "son of the Smith", has also been suggested, whilst lastly the MacNairs of Ulster are said to derive from Mac an Mhaoir, meaning the son of the steward or keeper. This family held the hereditary post of keeper of the Book of Armagh at Ballymoyer which translates as the town of the keeper. The first recorded spelling of the family name is shown to be that of Andrew Mcnayr. This was dated 1392, in the Acts of parliament in Scotland, during the reign of King Robert 111rd, of Scotland, 1390 - 1406. 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.