This unusual and interesting surname has its origins in the popular medieval female given name "Sibley", a vernacular form of the Latin "Sibilla", ultimately from the Greek "Sibylla", a title borne by various oracular priestesses in Classical times who claimed to be able to interpret the wishes of the gods through their oracles. Virgil describes how the Cumaean Sibyl helped Aeneas to reach the Underworld to see the spirit of his father, by means of a Golden Bough, and in Christian mythology the sibyls came to be regarded as pagan prophetesses of Christ: seven of these are depicted by Michelangelo on the ceiling of the Sistine Chapel in Rome. The name was initially brought to England by the Normans in the wake of the 1066 Conquest, and the surname was first recorded in the latter part of the 13th Century (see below). Further early examples of same include: Thomas Sibely (Cambridgeshire, 1275); William Sibli (Huntingdonshire, 1279); and Richard Sebely (Suffolk, 1327). In the modern idiom the name is variously spelt: Sibley, Sibly and Sebley. Two notable bearers mentioned in the "National Biography are George and Septimus Sibley: the former was chief engineer of the north west provinces of India (1859), and founded engineering scholarships at Calcutta, and the latter was a physician who published a work on the cholera epidemic of 1854. The first recorded spelling of the family name is shown to be that of Geoffrey Sibilie, which was dated 1273, in the "Hundred Rolls of Suffolk", 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.