This interesting surname of English origin is a locational name from a place called Clitheroe in Lancashire, deriving from the Old Norse "klithra" meaning "song - thrush" plus "haugr" "hill". The surname dates back to the late 12th Century, (see below). Further recordings include one Robert de Cliderhow (1316), rector of Gargrove in Craven recorded in "The History and Antiquities of Craven", Johannes Cledrow (1379), "The Poll Tax Records of Howdenshire", and Robert Cletherowe (1439), "The Register of the Freemen of the city of York". Variations in the idiom of the spelling include Clithroe, Clitherow, Cleatherow, Cluderay, etc.. Anne, daughter of Henry Clitherowe, was christened at St. Dunstan in the East, London, on December 21st 1576. Benjamin, son of Thomas Clethereo, was christened at St. Olave, Hart St, London, on November 1st 1583, and Nathanael Clitheroe married Sarah Colson on December 29th 1727, at St. Nicholas Cole Abbey, London. The first recorded spelling of the family name is shown to be that of Thomas de Cliderhou, which was dated 1176, in the "Pipe Rolls of Yorkshire", during the reign of King Henry 11, known as "The Builder of Churches", 1154 - 1189. 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.