I wonder if Hugh Roberts could have wrongly interpreted the comments in Garrard's ledger, as far as the Lesser Stars of Africa (i.e. the Cullinans III and IV) are concerned.
Let's sum up what we know:
- on 20th May 1911, the Illustrated London News publishes pictures of Queen Mary wearing the "Durbar" tiara, in an all-diamond version, with the Cullinans III and IV set at the front of the tiara. This picture is from that same photo session:
So this picture, and the ones posted by Beth at the beginning of this thread, dismiss two commonly shared errors: 1) that the Durbar tiara was first worn for the Delhi Durbar in December 1911 2) that the Durbar tiara was altered in order to take the Cullinans III and IV only in 1912, as erroneously written in Hugh Roberts' The Queen's Diamonds.
- on 11th December 1911, the Delhi Durbar took place. Queen Mary wore the Durbar tiara for the first time in public, and for the first time in the emerald version (with the Cambridge emeralds topping the tiara, including one of the emeralds replacing the pear-shaped Cullinan III). The large square Cullinan IV had been removed and replaced by a circle of small diamonds, surrounding a square diamond:
- Queen Mary wore the tiara in the same version, probably at the same time as the Delhi Durbar (judging from her physical aspect):
- in 1912, Queen Mary wore the Durbar tiara for the first State Opening of Parliament following the Coronation. The tiara was still topped with the Cambridge emeralds, but the Cullinan IV was set again at the front of the tiara - except that it was not set horizontally (with the angles at N/S/E/W), but diagonally (with the angles at NW/NE/SE/SW):
- on the following two pictures (undated, but visibly from the pre-WW1 years), Queen Mary wears the tiara in the same setting:
- on 12th March 1922, Queen Mary wore the Durbar tiara during a State visit to Belgium (or a Belgian State visit to Britain?). The tiara was in all-diamond version again (which matches with Hugh Roberts' comments that "the emeralds had been removed permanently from this tiara in 1922"), and the Cullinans III and IV are set at the front of the tiara. But the setting is different from the version seen above in May 1911: - as explained above, the square Cullinan IV is set diagonally, and not horizontally - while in 1911 the Cullinan III was sharply protruding above the top line of diamonds of the Durbar tiara (which gave, to be honest, a weird and unelegant look to the tiara), in 1922 the Cullinan III sits slightly lower, so that the top of the pear-shape sits in due line with the top line of diamonds of the tiara:
- on the following pictures, dated 1927 by the Royal Collection, Queen Mary wears the Durbar tiara again with the Cambridge emeralds, and with the Cullinan IV set diagonally at the front of the tiara:
- on 26th February 1947, during the Royal Tour to the Union of South Africa, Queen Elizabeth wore the Durbar tiara, in an all-diamond version. The Cullinans III and IV had been removed (Queen Mary had retained them), and the tiara was ornated with the setting of small diamonds already worn in December 1911 at the Delhi Durbar:
From all this visual evidence, we should conclude that the alterations mentioned by Roberts, from Garrard's ledgers at the date of 19th March 1912 and 14th May 1912, did not consist in adapting the Durbar tiara "to take either or both of the two Lesser Stars of Africa", as the Cullinans III and IV could be mounted onto the tiara as soon as May 1911. But I wonder if the alterations mentioned could have consisted in changing the setting of the Cullinan III (lower than in 1911) and of the Cullinan IV (diagonal setting, instead of horizontal).