What religion did they profess?

[Johann Salvator]

I need help regarding the religion of the former royal houses of Austria and Germany. My goal is to have a religious map of the former HRH. I am not interested on the religions of the current heads of these houses, I am looking for the historical map of these families. Also, it does not matter if the family is extinguished. There were a lot more Sovereign Houses extending far away from Austria and Germany, I am interested in those too. Thanks in advance for your contributions!

So far this is what I figured out:

Habsburg Catholic Church
Wittelsbach Catholic Church
Wettiner (Sachsen) Catholic Church

Hohenzollern Prussian Union (Evangelical Christian Church)

Württemberg Lutheranism
Mecklenburg-Schwerin Lutheranism
Mecklenburg-Strelitz Lutheranism
Wettiner (Sachsen-Altenburg) Lutheranism
Sachsen-Couburg und Gotha Lutheranism
Sachsen-Meiningen Lutheranism

Baden ¿?
Hessen ¿?
Oldenburg ¿?
Saxen-Weimar-Eisenach ¿?
Askanier (Anhalt) ¿?
Hannover ¿?
Lippe ¿?
Reuß jüngerer Linie ¿?
Reuß älterer Linie ¿?
Schaumburg-Lippe ¿?
Schwarzburg-Rudolstadt ¿?
Schwarzburg-Sondershausen ¿?
Waldeck ¿?

[Seraphine]

Hessen, Oldenburg, Sachsen-Weimar-Eisenach, Hannover, Schaumburg-Lippe, Waldeck, Anhalt, Lippe - definitely lutheranian

Württemberg changed back to catholic church 3-4 generations ago !

The former kingdom of saxony ( not to mix up with the many (grand-)dukedoms) - catholic church

Baden - many in southwest Germany are catholic, but they have married many women from protestant houses and have good relationships and contacts to them - so I guess they are protestant

Reuß - probably protestant

Schwarzburg - their heads daughter married in a catholic ceremony - so maybe they are catholic.

[MAfan]

As for the Wurttembergs, the main branch (that became extinct at the death of King Wilhelm II in 1921) was protestant (I think Lutheran, but I'm not sure exactly).
The other branch, of the present Dukes of Wurttemberg, is Catholic; if I don't mistake, they became Catholic when Duke Alexander married to Princess Marie of Orleans in 1835.

[Johann Salvator]

Thank you Seraphine and MAfan for your contributions.

Very interesting

[DWC]

Schwarzburg and Reuss were both Lutheran, some families like Saxe-Coburg and Gotha, Mecklenburg-Schwerin, Lippe, and Wurttemberg like Mafan mentioned, all had Catholic branches.

I can recommend an Almanach de Gotha which gives you the religions of the families if you are interested in any other families like the mediatised ones. Here is a link for you to the 1910 one.

Almanach de Gotha

[Ultramare]

Württemberg and Mecklemburg Streilitz-converted to Catholicism some years ago. Reuss has Protestant, Catholic and till Orthodox branches.