The royal house of the Jiménez (Ivrea) line that ruled Castile from the twelfth century until the Trastámara took the throne in 1369.
The Castilian royal house descended from the Jiménez dynasty of Navarre, whose greatest figure, Sancho III "the Great" of Navarre, dominated Christian Spain in the early eleventh century and parcelled out kingdoms among his sons. From this line came the kings who made Castile the leading power of the Reconquista.
Historians often call the Castilian branch the "House of Ivrea", after a distant Italian ancestor, to distinguish it from the later Trastámaras; contemporaries simply knew them as the kings of Castile.
The dynasty’s central achievement was the war against Muslim al-Andalus. Alfonso VIII suffered a shattering defeat at Alarcos in 1195, but in 1212, at the head of a coalition of Iberian kings, he crushed the Almohads at the Battle of Las Navas de Tolosa — the decisive victory that broke Muslim power in the peninsula and opened Andalusia to Christian conquest.
Under his successors Castile absorbed Córdoba, Seville, and much of the south, becoming the largest of the Spanish kingdoms.
After a turbulent fourteenth-century minority, Alfonso XI restored strong royal government, defeated a last great Moroccan invasion at the Salado in 1340, and issued important law codes. His son Peter — remembered as "the Cruel" or "the Just" depending on the teller — ruled harshly and made many enemies.
Peter’s wars against his illegitimate half-brother Henry of Trastámara drew in England and France as a theatre of the Hundred Years’ War.
In 1369 Henry of Trastámara killed Peter the Cruel at Montiel and seized the throne, ending the Ivrea line and founding the Trastámara dynasty that would eventually unite Spain.
The House of Ivrea left Castile the dominant power of Christian Iberia, its Reconquista carried almost to completion and its royal institutions and law firmly established.