 On the other hand, a Celtic origin of the name has been suggested to, from the word "casurus", which would date back to the Gaulish domination, which might suggest that the town's origins are even older than the generally accepted theory of a Roman origin.In 865 AD, a document makes reference to "Catoriacum" or "Catoriaco", which is believed to be a reference to Casorate.In 1193, it seemed to be called "Caxeradho".