Hi I have a question about what I bought at a thrift store in 2nd district.

I’m sorry if this isn’t the best thread to ask this question, but would anyone have any idea as to information on this plaque?
I can see that on the right is Franz Joseph and on the left is Maximilian I (an emperor of the Holy Roman Empire). From what I’ve translated so far I understand the writing says “In Memoriam of the Austrian empire constituted in …..”

Any information as to why these two leaders are depicted together would be really appreciated! Thanks so much!

by Foxhound_98