Before the Nazi era Franconia was as a region with significant Jewish communities, most of whom were Ashkenazi Jews. The first Jewish communities appeared in Franconia in the 12th and 13th centuries and thus later than, for example, in Regensburg. In the Middle Ages, Franconia was a stronghold of Torah studies. But Franconia also began to exclude the Jewish populations particularly early on. For example, there were two Jewish massacres - the Rintfleisch massacres of 1298 and the Armleder Uprising of 1336-1338 - and in the 15th and 16th centuries many cities exiled their Jewish populations, which is why many Jews settled in rural communities. Franconia also rose to early prominence in the discrimination of Jews during the Nazi era. One of the first casualties of the organized Nazi persecution of Jews took place on 21 March in Künzelsau and on 25/26 March 1933 in Creglingen, where police and SA troops under the leadership of Standartenführer Fritz Klein led a so-called "weapons search operations".Whilst, in 1818, about 65 per cent of Bavarian Jews lived in the Bavarian part of Franconia, today there are only Jewish communities in Bamberg, Bayreuth, Erlangen, Fürth, Hof, Nuremberg and Würzburg and in Heilbronn in Baden-Württemberg.. When were the Ashkenazi communities significant in Francnonia?