The Collaborative International Dictionary of English v.0.48:

Patesi \Pa*te"si\, n. [Assyrian.] (Babylonian Antiq.)
   A religious as well as a secular designation applied to
   rulers of some of the city states of ancient Chaldea, as
   Lagash or Shirpurla, who were conceived to be direct
   representatives of the tutelary god of the place.
   [Webster 1913 Suppl.]