It can be stated with reasonable certainty that this name is locational, of Olde English origins, and derives from residence at a place called something like "Colbroc" at the time of Domesday Book in 1086. However there are a number of such places, although the principal area is Devon where no less than five places, have at various times been so-called. It is from Devon (see below) that we have the earliest of all known recordings, although it is also reasonably certain that the Oxford parish made some contributions. The name probably means "The cool brook" but it could also describe a place where "colliers" operated. This does not describe Coal Miners, but makers of charcoal, an important fuel in the pre medieval period. The Coat of Arms of Colebrook is red with an ermine lion rampant, and a crest of a wyvern (flying dragon), suggesting a person of noble and high aims, and one who can guard his possessions. The name recording examples include Elizabeth Colbrocke of Clerkenwell in 1575, Barbara Coulbrook, who married John Hall, at Watlington, Oxford, on July 1st 1640, and Joan Hamly Colebrooke, who married Rodges Ballamy at Ide, Exeter, on October 22nd 1678. The first recorded spelling of the family name is shown to be that of Henry de Colbrok, which was dated 1273, in the Hundred Rolls of Devon, during the reign of King Edward 1, known as "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.