Recorded in the spellings of Sidnell and Sidnall, this surname is of Olde English pre 10th century origins. It is locational and derives from a place which was probably called 'Sidwell', a lost medieval village which may have been in Devon. The changes to the surname are accounted for by dialect and poor spelling particularly in the 15th and 16th centuries, when there was considerable civil unrest in England. This later lead to civil war in 1641. If this is correct the name means 'the spring (waella) in the broad valley (sid)'. The 'modern' surname is most popular in the London area, which is logical, because it is to London that the people of 'lost' villages tended to gravitate. Examples of the name recording include John Sidnall, christened at St Brides church, Fleet Street, on November 24th 1639, An Sidnell who married James Jenkinson at St Nicholas Cole Abbey, on December 8th 1698, and Eliza Sidnell, who married Robert Frisby at St Dunstans in the East, Stepney, on September 27th 1840. The Coat of Arms has the blazon of a blue field, a gold fess between three silver crescents, indicating victory at sea over the infidel. The first recorded spelling of the family name is shown to be that of Elysabeth Sydnale, which was dated August 23rd 1570, who married John Bocket at St Michaels Bassinshaw, during the reign of Queen Elizabeth 1, known as 'Good Queen Bess', 1558 - 1603. 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.