SOURCES: websites, books
The ethnic origin of the surnames ending in –at has long been a personal study. Very early in my research I found the following quotation and quoted it on the first page of Chapter I of her 2010 book. See https://suwalkigermans.wordpress.com/2012/06/07/whats-in-a-name-5/
…Lithuanian surnames suffixes which are found in Germany among families formerly in [the] Memel, Tilsit, and Heydekrug administrative districts of East Prussia. In German, these suffixes [are] usually shortened to the –at or –eit form, thus Petschulat, Josupeit.[i]
Continued print and online research between 2010 and 2015 resulted in this 2015 summary:
This linguistic evidence has been documented for decades. German genealogical publications contain several articles in which various experts (some with –at names) explain the linguistic sources of these names.
Among the many Internet articles that discuss this subject are: See
http://surnames.behindthename.com/submit/names/usage/german-east-prussian This website provides a list of East Prussian names.
wiki-de.genealogy.net/Memelländische_Familiennamen This site concentrates on the endings and special Baltic Surnames of Memelland (Endungen und Besonderheiten baltischer Familiennamen …) http://translate.google.com/translate?hl=en&sl=de&u=http://wiki-de.genealogy.net/Memell%25C3%25A4ndische_Familiennamen&prev=search
http://translate.google.com/translate?hl=en&sl=de&u=http://www.familie-loyal.de/%3Fq%3Dnode/10&prev=search Small Dictionary of Lithuanian Surnames (Kleines Lexikon litauischer Familiennamen) provides a list compiled by a webmaster of Lithuanian surnames.
The German surnames ending in –at are of Lithuanian origin with an –aitis spelling, but when written in German, they are “truncated” (shortened) to the –at ending. These names originated in northern East Prussia, today divided between Lithuania and the Kaliningrad Oblast (an administrative division corresponding to an autonomous province) in Russia.
The following two excerpts from most knowledgeable researchers reflect the variations of this suffix:
Spurgat is almost certainly a Lithuanian name. The last part was probably “-aitis” which means “the son of”, as does “-unas”; “-aitus” was usually abbreviated in East Prussia to just “-ait”, and often written as “-at.” Lots of Poles, Russians, Lithuanians, Old Prussians as well as Germans in East Prussia made for some strange spellings.
… Therefore I think that Spurgat (Spurgaitis, Spurga)… is of Prussian origin and not of Salzburgers or of mainland Germany.
Internet research and these two sources raise the question of, “Who were the Prussians?”, a topic I had not addressed in 2010.
The Pruzi (aka Prusai) were a native people who have come to be called the Old Prussians. The Pruzii lived along the lands of the southeastern Baltic Sea and spoke a now-extinct language known as Old Prussian. Over the centuries they were fused into other ethnic groups.
The best three maps I have ever seen that illustrate the movement of people in this area were observed on this website: http://forums.civfanatics.com/showthread.php?t=535483&page=2 The descriptions provided very specific information. However, in January 2016 this website was labeled very dangerous and may be blocked by Norton Anti-virus software. Just prior to posting this on May 1, 2016, I typed Colonization of the Prusai in the search window of the website and after scrolling down, the maps by Domen in March 2009 were there.
Out of this mixture of peoples (clearly shown on the maps), the German culture eventually became dominate. Not only did the mixture of people emerge as German, they were also Lutheran and the two became synonymous. The language of the church and Sunday school was the language of the home.
In 2010 the author had written that the Spurgats were German for two reasons: language and religion. A clearer understanding is that the German language and the German religion are inseparable. Together they form one reason to be German, not two.
Gradually through assimilation of the German culture, rulers, government, language, and church, the Prussian people, their language, and their culture became extinct. A basic tenet of the Protestant Reformation was that the Bible should be available to the people to read in their native language. One author states that the reason that the Prussian language became extinct is that no native Prussian speakers were available to translate the Bible in the 16th century into the Prussian language.
What I written in 2010 was still true in 2015:
It is one of the great ironies of history that the term Prussian remains even though the Prussian people do not exist. Today the Pruzi are often referred to as the Old Prussians. It has been said that the last pure blood Prussian died in 1803.
The third map is an 1847 map of German Ethnicities. I interpreted the map in the following way: East Prussia is in green. The border of East Prussia is red. The (green) center left area in the north-west territories (Bartenst.) shows the German-speaking majority. The (yellow) lower half in the south shows the territories (Allenstein) with Polish-speaking majority. The (purple-grey) area, the upper right in the northeast, shows the territories (Insterburg) with Lithuanian-speaking majority nearest where people with my -at name have been located.
[i] Clifford Neal Smith and Anna Piszczan-Czaja Smith, Encyclopedia of German American Genealogical Research (New York and London: R. R. Company, no date), 94.