The Delhi Durbar Tiara (Photo: Bethany Clarke/Getty Images)

Let’s wrap up May with a look at one of the crowning achievements of Queen Mary’s impressive collection: the tiara she had created for the Delhi Durbar in 1911.

The durbar was a massive celebration held in Delhi to mark the coronation of King George V and Queen Mary as Emperor and Empress of India. It was also the only one of the Indian coronation durbars to be actually attended by the royals themselves; on other occasions, the viceroy general stood in. Here’s newsreel footage of the 1911 Durbar to give you an idea of its vast scope. You can see Queen Mary is wearing the tiara in the film.

Queen Mary wears the tiara with the emerald toppers (Photo: Grand Ladies Site)

For such an event, the new empress needed a truly impressive tiara. She had one of her other sparklers, the Boucheron Loop Tiara, dismantled so that the diamonds could be used by Garrard in 1911 to create this piece. Originally, the tiara was also topped by several pear-shaped gems from the Cambridge emerald cache. But ever crafty with her jewels, Mary had those emeralds removed in 1922; they were then remade so that they could be used in the Vladimir Tiara.

Queen Mary wears the tiara with the Cullinan stones (Photo: The Royal Collection)

The Cambridge emeralds weren’t the only stones that May sometimes wore with the Durbar tiara — she also occasionally wore it with the Cullinan III and IV diamonds (the two “Lesser Stars of Africa” or “Granny’s Chips” — the queen today wears these two diamonds as a brooch, and it’s the single most expensive piece of jewelry she owns).

Queen Mary gave the tiara to her daughter-in-law, Queen Elizabeth, as a permanent loan in 1946; the Queen Mum wore it on the family’s tour of South Africa the following year. She kept the tiara until her death, when it was inherited by the current queen. Elizabeth II has never worn this particular tiara in public.

Camilla wears the tiara (Photo: MATT DUNHAM/AFP/Getty Images)

In 2005, it was one of three tiaras that she loaned to her new daughter-in-law, the Duchess of Cornwall (the others are the Greville Tiara and the Teck Crescent Tiara). Camilla has so far worn the Durbar tiara only once, in October 2005 — here’s hoping we see it again someday soon!