monarchize

verb3

1. •
   To convert to a monarchy.

   • […] so far we shall be from mending our condition by monarchizing our government, whatever new conceit now possesses us. — 1660
2. •
   (no longer used) To rule; to govern

   • We must confesse, she can all Soules subdue, — 1612
3. •
   (no longer used) To act or play the part of a monarch.

   • Uice hath golden cheekes, O pittie, pittie, She in euery land doth monarchize. Uertue is exilde from euery Cittie, Uertue is a foole, Uice onely wise. — 1600