‘King Ferdinand” is a character taken from which play?

The play opens as Ferdinand, the king of Navarre, and three of his noblemen—Berowne (Biron), Longaville, and Dumaine (Dumain)—debate their intellectual intentions. Their plans are thrown into disarray, however, when the Princess of France, attended by three ladies (Rosaline, Maria, and Katharine), arrives on a diplomatic mission from the king of France and must therefore be admitted into Navarre’s park. Source: https://www.britannica.com/topic/Loves-Labours-Lost-by-Shakespeare