This is a residential surname. It describes a person who lived in a 'casa,' a word with varied meanings as shown below, and recorded in over eighty spelling forms. Although medieval, it has pre Christian Roman origins. As a surname and indeed a place name it is recorded throughout Northern Europe including the British Isles, France, Italy and Spain. The surname spellings include Casa, Casio, Caso, dell Casa, Castello (Italian & Spanish), Castle, Castell, Castles (English & Scottish), Casillis, Chasal, Chasel, Chazel, Chazelas, Chazelle, Chazelles (French & Belgium), and many others. However spelt it described a person who lived in a mansion house or castle, often in a town square, and usually the most important dwelling in the settlement. The surname has many aristocratic holders including the counts of Casillis, members of the Spanish nobility, or the counts of Chazelles, from the Langedoc region of France. The following recordings taken from ancient civil and religious registers provide a number of examples including Hernando de la Casas of San Estaban, Vizacaya, Spain, on February 9th 1573, and Francoise Charles Chazelles, who married Maguerite Husson, on July 29th 1681, at Blamont, in the department of Meurthe-et-Moselle, France. A coat of arms associated with the name has the blazon of a silver field, charged with a red chevron between three cross-crosslets, inside a red border. The first recorded surviving continental spelling of the family name is possibly that of Quitteria Casas. This was dated 1324, at Medina, Gerona, Spain. Surnames became necessary when governments introduced personal taxation. In England this was sometimes known as Poll Tax. Throughout the centuries, surnames in every country have continued to "develop" often leading to astonishing variants of the original spelling.