Prince Constantin of Liechtenstein passed away in December 2023. I had written to Prince Constantin's father, Prince Hans-Adam to express my condolence to him & Prince Constantin's family. And I had also mentioned my condolence for Prince Constantin in my Christmas card to Hereditary Prince Alois. I received a reply from both of them.
The envelopes for both replies was the same and features black mourning edge.
The back features a crown above "Vaduz" the name of the Luxembourg's castle.
The two cards are identical, except for signatures. They features a embossed coat of arms along with a typed message.
I've compared the signatures with past replies I have gotten from them and the signatures are not identical which makes it seem like they are real. But we do know they use Auto pens.
The card says "With many thanks for your kind sympathy."
This first card is signed by Prince Hans-Adam and is signed "Hans-Adam Liechtenstein." Prince Hans-Adam is the late Prince Constantin's father.
This card is signed by Hereditary Prince Alois, Prince Constantin's older brother. It is signed "AL" for Alois Liechtenstein.