In Shakespeare play, Cymbeline is the king of-

Cymbeline, comedy in five acts by William Shakespeare, one of his later plays, written in 1608–10 and published in the First Folio of 1623 from a careful transcript of an authorial manuscript incorporating a theatrical playbook that had included many authorial stage directions.
- King Cymbeline of Britain banishes his daughter Innogen's husband, who then makes a bet on Innogen's fidelity. Innogen is accused of being unfaithful, runs away, and becomes a page for the Roman army as it invades Britain.
In the end, Innogen clears her name, discovers her long-lost brothers and reunites with her husband while Cymbeline makes peace with Rome.

Source: Britannica and Shakespere.com