For the interessed, an article about the guide Strategikon. Which was supposaly writen by the East-Roman emperor Mauritius I.
I found the article, a link in wikipedia, while searching some information about Roman taxes and the Codex Iustiniani.
It is a praised quide, however many never have heard of it (including me, until this accidental encounter).

The link is:

http://www.au.af.mil/au/awc/awcgate/strate...strategikon.htm