They lost control of Brunswick. The name of their bloody duchy.They honestly seem to have done one of the best jobs at deciding all that territorial splitting was a bit much it has to be said.
They also got it back shortly after the Thirty Years War, which is a damn sight better than many others.They lost control of Brunswick. The name of their bloody duchy.
Granted, that happened all the time in the HRE, most notably with the Archbishop of Cologne being forbidden to set foot in the city, I believe, but still!