Pedro I de Castilla (3 book series) Kindle Edition - Amazon.com
The trilogy centers on Pedro I of Castile (reigned 1350–1369), a monarch whose legacy remains a subject of historical debate. Known to his enemies as "The Cruel" and to his supporters as "The Justiciero" (The Executor of Justice), Pedro's life was defined by a brutal struggle for power against his illegitimate half-brothers, the Trastámara family.
If you are looking for a deep dive into 14th-century Castile, Alfonso Solís's historical trilogy about King Pedro I is a masterful choice. This series—comprising (Of Kings and Bastards), De Leales y Traidores (Of Loyalists and Traitors), and De Crueles y Justicieros (Of Cruels and Justiciars)—plunges readers into one of Spain's most turbulent eras. The Legend of the "Cruel" or "Just" King