How cute isn't it, that the family's original fief Windischgrätz / Windischgratz is called Slovenj Gradec today!
And of course Graz, the capital of Styria, has the same etymology! gradets, a small castle / town, just like the Фёдоровский городок in Tsarskoe Selo.
That is of course why one needed to distinguish Windisch-Gratz from (Deutsch-?)Graz.
And LOL, German-speaking Graz was founded with a Slavic name, while also predominantly German-speaking Windisch-Grätz was known as windisch, i.e. Slavic / Slovene.
I wonder if there is a Welschgratz > Grazza Italiana!?