Julian and the invasion of Persia

[Mithras]

Hah, that makes everything much clearer to me; I don't know much about the federation of Goths into the army. So, had Julian taken a numerus of Goths with him into Persia, it would almost certainly have been a different contingent than that which Procopius used. Very interesting. As a member of the Constantinian bloodline, can I assume that Julian had good claims when demanding the Goths provide him troops?

...the 3000 Goths Ammianus mentions have quite probably to be referred to the treaty between Constantine e Goths: it was a contingent Goths had to supply to Romans upon request (details are still debated , but this seems to be the the right way of understanding it), which was formed up and supplied when needed; it was not a permanent unit related to Roman Army, and certainly had not the standard organization of a Roman unit.