Right - 18th Century large brass gorgets, called a “Ferahi”, worn by the Sultan’s security personnel for his court [1].
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[1] From Metin Erüretin. (2001) Osmanli Madalyalari ve Nisanlari [Ottoman medals and orders: documented history]. DMC: 155.
Far Right - These figures show small plates mounted under the collar, one either side of the jacket buttons.
Right - General Vanson recorded seeing in the Crimean War [1]:
These were worn by a “Mounted Artilleryman (General Vanson); a composite from another sketch titled 'Campaign Artillery', and a detailed description of a horse artilleryman on guard duty'. Identified as wearing [2]:
Right - "Turkish Soldiers in Summer Uniform" (1853) painted by Count Amadeo Preziosi, in Constantinople. There are some important features to note about these uniforms:
(1) The infantry soldier has a pair of metal square plates fitted under his collar.
(2) Note as well: the cuff is closed with three large tunic buttons.
Right - Illustrated as a 'Turkish Foot Soldier (1854)', from sketches of character and costume in Constantinople, Ionian Islands &c. from the original drawings made on the spot by Capt'n. Forbes Mac Bean, 92nd Highlanders, lithographed by J. Sutcliffe.
Below - An example is pictured in Metin Erüretin. (2001) Osmanli Madalyalari ve Nisanlari [Ottoman medals and orders: documented history]. DMC: 155.
Above - This plate likely evolved into the versions illustrated from the 1850s (discussed above), the pair of plates were now manufactured with a visible 'globe' deeply embossed into each plate, one bearing the Sultan's Tugra, the other Ottoman script (in keeping with the original 1830s version).
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[1] [2] C.A. Norman. Turkish Uniforms of the Crimean Era (Soldiers of the Queen: Issue 85).
Right - An 1845 painting by Women of the Sultan's harem on their promenade [1],
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[1] Painted by Jean Brindesi, from the book 'Souvenirs de Constantinople (Paris, Lemercier, 1845).
Right - An illustration of the 1854 Interior Guard (Beylerbey Palace): Sultan's Halberdier Bodyguard uniform [1].
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[1] Jack Cassin-Scott, John Fabb, 1973 Ceremonial Uniforms of the Eorld, Hippocrene Books: Plate 73.
[2] Jack Cassin-Scott, John Fabb, 1973 Ceremonial Uniforms of the Eorld, Hippocrene Books: Plate 44 description.