Ross Cowan was formerly a research student at the University of Glasgow where he was recently awarded a PhD for a thesis on the Roman army entitled 'Aspects of the Severan Field Army AD 193-238'. The major themes of the thesis are the organization of the Praetorian Guard and Legio II Parthica, their recruitment, numbers and equipment. Ross also completed his first degree at Glasgow. In 1999 he was elected a fellow of the Society of the Antiquaries of Scotland. The author lives in Glasgow, Scotland.Ross Cowan was formerly a research student at the University of Glasgow where he was recently awarded a PhD for a thesis on the Roman army entitled 'Aspects of the Severan Field Army AD 193-238'.… The major themes of the thesis are the organization of the Praetorian Guard and Legio II Parthica, their recruitment, numbers and equipment. Ross also completed his first degree at Glasgow. In 1999 he was elected a fellow of the Society of the Antiquaries of Scotland. The author lives in Glasgow, Scotland.