The Austrian Emperor was always ready to stage another attack on Napoleon. When the Austrian Emperor allowed Napoleon to marry his daughter, many hoped this would mean peace. Wrong.
I have wondered if Emperor Franz knew his daughter was bad luck and that it was a devious move to send his daughter to Napoleon. At the reversal of fortune, the Austrian government turned on Napoleon. That government took their princess back - AND Napoleon’s son. Napoleon's son had been an energetic youth who admired his father. They changed the boy’s name from Napoleon to Franz. Napoleon’s son (under the “care” of his grandfather Emperor Franz) was dead by 21.
Listen to this amazing story here.