The "destroyed Column of Theodosius"

[John Conyard]

My old wargames armies are full of Roman "Heavy Cavalry" with caparisons fastened in front of the horses chest. These representations seem to stem from Phil Barker's "Armies and Enemies of Imperial Rome" published by the Wargames Research Group. I have the 1979 and 1984 editions. The book gives an illustration of a Late Roman Heavy Cavalry Horse with a cloth barding or caparison, based on "surviving sketches by two separate artists of the destroyed Column of Theodosius". Sadly there are no detailed references.

Late Roman cavalry are taking up too much of my time at present. Does anybody have any information on these sketches of the lost column? It would be a help.