In Holly Black’s The Cruel Prince, the faerie king who rules Elfhame is Eldred.
Eldred is the High King of Elfhame and the father of several important figures in the royal court. His reign forms the political background for Jude Duarte’s struggle to gain influence among the immortal faeries.
The novel gives major attention to Eldred’s son Cardan, who is a prince rather than the reigning king at the beginning of the story. This distinction is a common source of confusion when identifying the monarch.
Madoc is Jude’s adoptive father and a powerful general, while Dain is another royal son. Their relationships create competing loyalties within Elfhame’s court and drive much of the book’s intrigue.