the word entered english from turkish "bey", itself derived from old turkic "beg", which - in the form "bäg" - has been mentioned as early as in the orkhon inscriptions (8th century ad) and is usually translated as "tribal leader". the actual origin of the word is still disputed, though it is mostly agreed that it was a loan-word, in old turkic. this turkic word is usually considered a borrowing from an iranian language. however, german turkologist gerhard doerfer assessed the derivation from iranian as superficially attractive but quite uncertain, and pointed out the possibility that the word may be genuinely turkic.