This tiara started life as a necklace originally owned by the Empress Josephine (wife of Napoleon). The necklace consisted of fifteen very large amethysts, surrounded by diamonds set in silver.
The Empress Josephine gave it to a relative of hers, Princess Augusta of Bavaria, who gave it to her daughter Josephine who married King Oscar I of Sweden in 1823. It's been owned by the Swedish royal family ever since.
In the 1970's, Queen Silvia of Sweden decided to turn it into a tiara. Here she is wearing it:
And here is a side view of Crown Princess Victoria wearing it:
