Увы, нагуглил только ссылку на Википедию. Впрочем там дана ссылка.
>Дык, хотелось бы точно знать откуда. И каким образом.
http://en.wikipedia.org/wiki/Reich Reich has an interesting etymology: it comes from a Germanic word for "king", which was borrowed from Celtic. (See Calvert Watkins, American Heritage dictionary of Indo-European Roots, p.70.) It has cognates in many other languages, all ultimately descended from the Proto-Indo-European root *reg-, meaning "to straighten out" or "rule", also the source of English right.