This unusual surname is of ancient pre Celtic origin, found in Scotland and Northern Ireland and is a topographical surname for someone who lived on the banks of the River Clyde, which flows through Glasgow. The river name derives from the Gaelic name "Cluaidh", the meaning of which is so ancient as to be obscure. The "Compt Book" (accounts) of David Wedderburne, merchant of Dundee 1587 - 1630, records one William Clyde, admitted burgess of Dundee in 1580 and the Lanark Register of Testaments 1595 - 1800 records the Will of one Helen Clyde, of the town of Belstaine, parish of Carhike, in 1665. William Clyde married Jane Parkehill at Paisley in Renfrewshire on the 10th February 1682. The first recorded spelling of the family name is shown to be that of Willelmus Clide, witness, which was dated 1493, Memoirs of the Maxwells of Pollok, during the reign of King James IV of Scotland, 1488 - 1513. 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.