There are believed to be two origins for this unusual name which is a transposition. The first is locational and derives from the village of Gilby in the parish of Pilham near Lincoln. There are at least six spellings of this name which strongly suggests a wholesale emigration in the medieval period and hence the wide range of spellings which are known to include Gillbee and Gillbey. The second possible derivation is from Gilbert, for which there are over fifty variant spellings including Gilburd, Gilbord and Gilberton. The first recorded spelling of the family name is shown to be that of Richard Gilbie of Lincoln which was dated 1571 The Oxford University Register. during the reign of Queen Elizabeth 1 Good Queen Bess 1558 - 1603 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.