Cymbeline (sĭmˈbəlēn) [key] or Cunobelinus kyōˌnōbĭlĪˈnəs, d. c.A.D. 40, British king. His conquest of the Trinovantes (of Essex) reportedly made him the wealthiest and most powerful ruler in SE England. After his death his kingdom was divided between his sons Togodumnus and Caractacus. Cymbeline gives his name, but little else, to Shakespeare's Cymbeline.