It somehow happened, as being said before, during the Mongol invasions.
Maybe otherwise more powerful and widespread Pagan Viking invasions until 11th Century. Maybe an organised Norse (Germannic) war cult calli g fore eternal conquest and looting. Maybe even Spanish Emirates threatened by...
The Lusatian-Polish-German War, 1901-1923
A seperatist war between Catholic Lusatian Sorbs and Poles on the one side and the German-Prussians on the other. Poles and Sorbs allied themselves in a Pan-Slavic uprinsing against the Germanisation policies of The German Empire/Prussia. In a manifesto...
OTL the GDR had on Democratic government (Lothar de Maziare DSU) before voting to rejoin Germany. The other condtion was the 4+2 conference in Berlin with all Allied Powers agreeing on letting bith Germanys merge. Merkel hat been part of the last East German government. Maybe ATL there are...
A 19th Century Jewish homeland as a monarchic kingdom (divine principe) would be interesting. An israelite King whoe sees himself as a peer of the Catholic and Protestant monarchs of Western Europe. Maybe Kingdom of Israel.