Recorded in a very wide range of spellings including Cecely, Cysely, Sisley, Sicily, and shortforms Cess, Cesse, Siss, Sise, Syce, Sisse and Size, this is an English surname. It is a nickname form of the popular medieval female name Cecilia, itself from the Roman (Latin) word 'caecus' meaning blind. The name was borne by a second century Roman virgin and martyr, popularly regarded as the patroness of music. Her name was introduced into the British Isles by the Norman-French after the Invasion of 1066, and is first recorded in the year 1200 when Henricus filius Cecilie appears in the Pipe Rolls of Derbyshire. This was not however a surname or was even hereditary, the first surname from this source is recorded in the latter half of the 13th century as shown below. Nicknames which developed into surnames formed one of the largest groups in the surname listings. In this case we have the added curiosity in that this name is one of the small group of metronymics, that is to say a name from the mother perhaps because she was the heiress, rather than the patronymic from the father. Early recording examples include Audrey Sys, a witness at St Margarets Westminster on January 19th 1541, and Elizabeth Size, who was christened at St Botolphs Bishopgate, on May 20th 1660, both in the diocese of Greater London. The first recorded spelling of the family name is shown to be that of Henry Cecili. This was dated 1279, in the Hundred Rolls of Cambridgeshire. Throughout the centuries, surnames in every country have continued to "develop" often leading to astonishing variants of the original spelling.