After a great deal of research about the -at names, I came to the following conclusion about my own family name. Whether or not this includes the -at names others researching their German Lutheran ancestors from Suwalki Province remains to be seen. Perhaps they will comment on this blog.
Researchers form a hypothesis, seek out all available information to support it, evaluate conflicting evidence, and draw conclusions based on their research. After a decade and a half of research, the author believes that the Spurgat family was German through language and religion, but that the Spurgat name is not of German origin.
The Spurgat name was popular in the 19th century in the eastern areas of what later became the German Empire.
- The Spurgat name does not appear in the most well-known German surname books.
- The Spurgat name with the Lithuanian spelling appears in the Lithuanian Surname Dictionary.
- Onomastics suggests that the Spurgat name is a Germanized version of the Lithuanian surname, Spurgaitis.
According to the authors of Germanic Genealogy: A Guide to Worldwide Sources and Migration Patterns, “A shared language…makes a common culture possible…. An ancestral mother tongue… [provides] a common heritage. And heritage matters.” These Spurgats spoke German in their homes well into the 20th century; some attended church services in German even after World War II. The German language makes the Spurgats German.
 Brandt, Germanic Genealogy: A Guide to Worldwide Sources and Migration Patterns, iv.