Originally Posted by
constantius
Valens was an Arrian ,but so were many in the empire .Arrianism had been the "party line " so to speak under ConstantiusII and in Constantines day Arrianism was Orthodox Christrianity.Theodosius was of a different creed and a supporter of 'one substance ' and decided to impose his will on the empire and in 381 Arrian bishops were deposed .The point is that there were lots of Christian groups ,Donatists in north Africa and still large numbers of pagans throughout the empire ,trouble only seems to arise when somebody imposes their own version of Christianity on others .
As for the battle itself ,the army that Valens had at Adrianople ,on paper should never have lost .It was experienced ,having served in the east ,its possible that the majority had served with him on the Danube against the Goths in 375 (although granted that is conjecture ) The failure down to poor intelligebce and the Goths had acheived complte tactical surprise ,when Gothic cavalry under Alatheus and Saphax with a strong contingent of Alanic allies ambused the Roman left wing that was advancing ahead of the rest .This then throws everyone into confusion and the left scatters ,allowing the cavalry to flank the Roman centre .