This interesting name has its origin in one of three possible sources. The most likely origin is habitational, from a place "Calver" in Derbyshire, so called from the Old English "c(a)lf", a calf and "ofer", a ridge. The Domesday Book for Derbyshire records the place "Caluoure" with the Pipe Rolls of Derbyshire entering it as "Caluore" and "Calfovr", in 1199 and 1239 respectively. The surname from this source first appears at the beginning of the 13th Century (see below). Secondly, it may be a variant of "Carver", a corner of wood or sculptor of stone (middle English "kerve(n)"), to cut, or carve, or from the Anglo Norman French word "Caruier", cart, plough, originally given as an occupational name for a ploughman. The first appearance of this name is when Peter le Caruier is mentioned in the Pipe Rolls of Nottinghamshire in 1203. There is also a possibility that the surname derives from "Calvert", a tender of cattle, from the middle English "Calfhirde (old English "Calf", calf and "hierde", a herdsman), which is common in the north of England and Northern Ireland. In 1269, one Warin le Calfhirde" is recorded in the Feet of Fines for Yorkshire and William Calvehird is entered in the Subsidy Rolls of Yorkshire in 1297. Mary Calver is mentioned in 1702 in the Shotley Parish Registers. The first recorded spelling of the family name is shown to be that of David de Caluenore or de Caluoure, which was dated 1200, The Pipe Rolls of Derbyshire, during the reign of King John, known as "Lackland", 1199 - 1216. 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.