This unusual surname is derived from the Olde English pre 7th Century personal name Chun, (of uncertain origin). It is recorded as a personal name in the Hundred Rolls of Cambridgeshire in 1273, (Chun Pimme, Chun Pistor). The surname appears in that year also (see below). We no longer see Chun as a personal name after the late 14th Century. Variations of the surname appear and recorded as follows, Hugh Chone in the 1275, the Pipe Rolls of Oxfordshire, Robertus Chaume in the Poll Tax Register for Yorkshire in 1379 whilst Thomas Chowme was found in Canterbury in 1688. The variant spelling as "Showan" is recorded in 1771 when Robert Showen married Elizabeth Bessell at Sunbury on Thames on August 5th of that year and in 1783 Elijah Showan was christened at Shoreditch on June 22nd. The first recorded spelling of the family name is shown to be that of William Chaum, which was dated 1273, in the Hundred Rolls of Lincoln, 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.