Alexander Sharon, an editor of the JewishGen Family Finder (JGFF) writes that according to the book, The legend of the Henrique House, by the author Yosef Ben Brit (written in Hebrew), the Cassirer name has original roots in Spain prior to the expulsion of the Jews and their arrival in Central Europe. The name Caseres is Jewish and is also the name of a small town east of the border of Spain with Portugal. Before the expulsion of Jews from Spain, there were comparatively fewer Jews in that region. Some of the family were born Christians, but continued some of the Jewish rituals. In Germany they changed their name to Kassieres (hiding the C in order obscure their origin). Some of the early relevant names include:
Fernao de Caceres ~1560
Leanor Lopes de Caseres,~1590
Antonio Dias Caseres. He served at the royal yard, became a sailor, immigrated to Mexico in 1598 where his name is in a list of heretics, posted according to custom in the cathedral in the city of Mexico. There are references to he and his wife Catalina de Leon, as 'Judaizers'; the latter doing penance at an auto da fé, celebrated on Feb. 24, 1590, in that city.
There is however another possible connotation to the name Cassirer as it subsequently became known in Germany. It may have become associated with the German word 'Kassierer' for Treasurer or 'Cashier'. This was certainly a historical view within the family. Writes Andrew Bano: "My grandmother, Lisbet Cassirer (married to Martin) was quite emphatic that the name derived from the synangogue official responsible for collecting money in the synagogue." (Andrew Bano, e-mail communication 8 Oct 2005.)
Professor Peter Paret has provided the following additional insights tending also to favour this family understanding:
"Two different and conflicting theories exist on the origin of the name Cassirer, and consequently on the family's early history. Cassierer = cashier derives from the Latin capsa = money box, and the Italian cassa. The word is German since the 16th century. In Yiddish, Cassierer was the Synagogue official who collected dues and fees from the Synagogue members. An alternate view suggests that the name comes from Caceres [as above], a town and area in western Spain, near the Portuguese border. Some 16th-century Jewish emigrants of that name are known, but their connection with Cassirers in eastern Europe has not been established. Both of these theories are plausible; neither has been adequately documented. In my view, the derivation of the name from an activity of individuals already living in eastern Europe is less complex and more convincing than that resulting from the possible emigration of a family in Spain. In either case it is certain that in the 1740s, after Prussia acquired Silesia in the War of the Austrian Succession, Jews living in Breslau needed to adopt family names on the West- and Central-European pattern, if they did not already possess them."
Professor Paret takes issue with the proposition from Yosef Ben Brit that the changing of the name to Kassieres was primarily to obscure the origin of the Cassierers. He notes that:
"The German language, in the course of the 19th century, was marked by a general tendency of changing C to K. This tendency was strongest in northern Germany, weaker in the south, and weakest in Austria, and it was never absolute. In the process, the word Casse changed to Kasse, Cassierer to Kassierer, Corps to Korps, Camera to Kamera, Cabel to Kabel, Carte to Karte, Capitain to Kapitän, etc., etc. Changing the name Cassirer to Kassirer has nothing to do with anti-Semitism, and certainly does not mask the name's Jewish antecedents."
[Peter Paret, e-mail private communication, 9 December 2004]