House of Trastámara

The House of Trastámara (Spanish, Aragonese and Catalan: Casa de Trastámara) was a royal dynasty which first ruled in the Crown of Castile and then expanded to the Crown of Aragon from the Late Middle Ages to the early modern period.

They were an illegitimate cadet line of the House of Burgundy who acceded to power in Castile in 1369 as a result of the victory of Henry of Trastámara over his half-brother Peter I in the 1351–1369 Castilian Civil War, in which the nobility, and, to a lesser extent, the clergy had played a decisive role in favour of the former.

After the succession crisis induced in the neighbouring Crown of Aragon by the death of Martin of Aragon without a legitimate heir, the 1412 Compromise of Caspe installed a member of the house of Trastámara, Ferdinand of Antequera, as monarch.

After the marriage of the Catholic Monarchs (both members of the house of Trastámara), Castile and Aragon came to be ruled under a dynastic union, even if a conflict, the War of the Castilian Succession, was waged between Aragon-supported and Portugal-supported parties over the throne of Castile, which was ensuingly confirmed to Queen Isabella. The dynasty was replaced by the House of Habsburg upon the effective enthronement of Charles V as king of Castile and Aragon in 1516, even though his allegedly mentally incompetent and imprisoned mother Joanna lived until 1555.

The resulting dynastic change saw a radicalization of the antisemitic sentiment in Castile, converging religious doctrinal anti-Judaism, aristocratic political antisemitism, and popular antisemitism exacerbated by the ongoing economic and social crisis, which had its climax in the 1391 pogroms.