Busy day today so I have picked a post that I can illustrate a lot.
Mamluks were the enslaved soldiers who served the Caliph in Persia, then in other countries, most notably Egypt. They were property but treated well and encouraged to compete for advancement. I find the set up interesting because it shows how a train of thought can be repeated. Local soldiers may have their own loyalties to family, tribe, governor but displaced persons far from home for whom compliance can reap huge benefits are far more likely to be devoted to the provider of those benefits.
Caligula and Nero chose Germanic slaves to form their body guards, and the Emperors of Byzantium had their Varangian guard, the Mamluks were selected from the strongest Georgians, Circassians and Kipchaks to be loyal to the Caliph and him alone.
As a military grade they were one of the longest lived organisations, existing from the 8th century AD until the early part of the 19th century.
Mamluk from Aleppo painted by William Page some time between 1816 and 1824.
Mamluk heavy cavalry armour c. 1550, bearing a resemblance to the armour used by the Sarmatians.
The last of the Mamluks – Roustum Raza, painted around 1793 by Vernet. Roustam was born in Tblisi and was purchaed as a body guard and personal attendant by Napoleon Bonaparte during the French invasion of Egypt. Roustam stayed with Napoleon until his death on St Helena, when he returned to France and settled in Dourdan. He died there in 1845 at the age of 61 or 62.