Queen Mary's Bandeau Trio

One, two, three! They could be triplets, nearly identical, each with a detachable centerpiece. One: Called simply and descriptively Queen Mary's Bandeau Tiara and worn by Meghan Markle on 19 May 2018, it has a detachable brooch made of ten brilliant diamonds. Queen Mary needed one of them to accommodate her County of Lincoln brooch, one of her plethora of wedding gifts, and so the diadem made famous by the Duchess of Sussex was fashioned.

Two: It was actually seen in public before that date and worn respectively by Queen Mary herself and Princess Margaret Rose. Queen Mary wore the band for the emerald brooch, by name the Delhi Durbar Carved Emerald Brooch; Princess Margaret wore the sapphire brooch.

Three: The "lozenge" tiara with 13 "pearl toppers" as Queen Mary wore it and "sans the pearl toppers" for Princess Margaret in 1948.