The Collaborative International Dictionary of English v.0.48:

Uncrown \Un*crown"\, v. t. [1st pref. un- + crown.]
   To deprive of a crown; to take the crown from; hence, to
   discrown; to dethrone.
   [1913 Webster]

         He hath done me wrong,
         And therefore I'll uncrown him ere't be long. --Shak.
   [1913 Webster]

Moby Thesaurus II by Grady Ward, 1.0:

37 Moby Thesaurus words for "uncrown":
   break, bust, cashier, deconsecrate, defrock, depose, dethrone,
   disbar, discrown, disenthrone, dismiss, displace, drum out,
   excommunicate, expel, give the gate, kick upstairs, liquidate,
   oust, overthrow, pension, pension off, purge, read out of, remove,
   remove from office, retire, strip of office, strip of rank,
   superannuate, suspend, unchurch, unfrock, unmake, unsaddle, unseat,
   unthrone