The first Jews, who gained urban rights, settled in Mrągowo in 1812. When in 1847 a permission to create synagogue municipalities was given, the Jews established one in the town, giving it the status of a county. The religious community in 1871 consisted of 230 members, and in 1905 - of 220.
The local Jews constituted a very diverse community as far as their wealth is concerned. They were making their living by trading in textiles, footwear, ironmongery etc. They worked as doctors and as support personnel in hospitals. They had integrated more and more with their Christian neighbors.
Izaak Dawidowitz (Icek Dawidowicz) was also mentioned. He arrived from Ełk and described the life of small Masurian town in Hebrew, German and Polish.
After the end of World War I the citizens of Mrągowo became less and less tolerant towards the local Jews. Persecutions and repressions were intensifying, together with the rise of support for NSDAP, before the Hitler's followers gained the full power. The culmination took place on “Kristallnacht”. Although the local synagogue was plundered, it was not burned down. The Jewish citizens of Mrągowo abandoned hastily the land of their fathers. In 1939 the Hitler's followers with pride announced that in the town and in the whole district even one Orthodox Jew did not live.
A great number of the Jewish citizens of Mrągowo hid themselves in Berlin, from where they were deported to places of extermination, directly or by going through ghettos e.g. the one in Theresienstadt. They were killed in camps in Auschwitz, Treblinka and Trawniki, and in ghettos in Theresienstadt, Łódź, Warsaw, Mińsk, Ryga and Piaski. A fair number of about 50 people connected with the town by birth or dwelling was murdered.
Members of the following families: Bütow (Bitov), Edelstein, Eisenstadt, Reissman, Schlochauer, Schmal, Schulz survived the Holocaust.
- Bitowt R., Materiały o przeszłości Mrągowa i ziemi mrągowskiej, Mrągowo 1999.
- Bitowt R., Nekropolie Mrągowa, „Mrągowskie Studia Humanistyczne” 1999, t. 1.
- Führer durch die jüdische Gemeindeverwaltung und Wohlfahrtspflege in Deutschland: 1932–1933, Berlin 1933, s. 26.
- Kossert A., Zapomniane południe Prus Wschodnich, Warszawa 2004.
- Unsere masurische Heimat, red. K. Templin, Sensburg 1918.