An interregnum and a war of succession began in the Kingdom of Portugal in 1383 when King Ferdinand I died leaving no sons and ended when King John I was crowned in 1385 after his victory during the Battle of Aljubarrota.
The Portuguese interpret the era as their earliest national resistance movement to counter Castilian intervention, and Robert Durand considers it as the "great revealer of national consciousness".
The Portuguese House of Burgundy (Portuguese: Casa de Borgonha) was a Portuguese noble house that ruled the County and later Kingdom of Portugal from its founding until the 1383–85 Portuguese Interregnum.
The house was founded by Henry of Burgundy, who became Count of Portugal in 1096. His son, Afonso Henriques, was proclaimed King of Portugal following his victory at the Battle of Ourique in 1139, establishing the Afonsine dynasty (Dinastia Afonsina). Burgundian monarchs would rule Portugal through much of its early formation, including the formalization of the Portuguese language under King Dinis I, the first Portuguese parliament, under King Afonso II, and the conquest of the Kingdom of the Algarve, under King Afonso III. Numerous princes of the house took up thrones across Europe, such as Ferdinand I, Count of Flanders and Peter I, Count of Urgell. Similarly, many princesses became royal consorts, including Berengaria, Queen of Denmark, Leonor, Queen of Aragon, and Teresa, Duchess of Burgundy, among others.