This interesting name has two possible derivatins, the first of which is of Anglo-Saxon origin, and is a locational surname from the place in Birmingham, Worcestershire, called 'Selly Oak'; the 'Oak' of the placename is a later addition. The place is recorded in the Domesday Book of 1086 as 'Escelie', and as 'Selleg' in the 1236 Fees Court Records of Worcestershire, and represents a Normanized form of the Anglo-Saxon placename 'Shelley', found also in Essex, Suffolk, Sussex and West Yorkshire. The name means 'the glade or thin wood on a slope', derived from the Old English pre 7th Century 'scylf, scelf', ledge, slope, with 'leah', glade, clearing in a wood, thin wood. The first recording of the modern surname, found as Selly and Selley, is from this source. The second possible origin is from the Medieval English nickname surname 'Sealey', for a person with a cheerful disposition, derived from the Middle English 'seely', happy, fortunate. 'Selley' and 'Selly' are variant forms, found mainly in Devonshire. William Selley and Elizabeth Howell were married in London in February 1669. The first recorded spelling of the family name is shown to be that of Richard de Selleia (witness), which was dated 1203, The Staffordshire Assize Rolls, 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.