This interesting name is of Anglo-Saxon origin, and is a locational surname deriving from any one of the places called "Blackden" or "Blagdon", or "Blagden farm" in Hempstead, Essex. Blackden in Cheshire, Blagden in Essex and Blagdon in Northumberland share the same meaning and derivation, which is "the dark or black valley", derived from the Old English pre 7th Century "blaec", black, with "denu", valley, while the places called Blagdon in Devon, Dorset and Somerset, recorded as "Blakedone" in 1242, "Blakeson" in 1234, and "Blachedone" in the Domesday Book of 1086 respectively mean "the black hill", derived from the Old English "blaec", black, and "dun", down, hill, mountain. The modern surname can be found as Blackden, Blagden and Blagdon. One John Blagden was christened at St. Mary Magdalene, Bermondsey, London, on December 28th 1595. The first recorded spelling of the family name is shown to be that of Roger de Blakeden, which was dated 1275, The Worcestershire Subsidy Rolls, during the reign of King Edward 1, "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.