This tiara is a Heirloom from Princess Isabella de Croy who married Duke Franz of Bavaria.
Their Son Ludwig married his first cousin Irmingard who wore it as Wedding tiara
Their Son Prince Luitpold's wife Beatrix wore it as Wedding tiara too.
Duke Luitpold daughers Princesses Beatrix, Alice and August wore the tiara also for their Wedding such as Dukes Ludwig and Heinrich wifes. What a great family heirloom !