[1] Although not much is known about his date and place of birth, with researchers debating whether it was Castille or Navarre,[2] it is, however, known that he was at the Court of King John II of Castile, as a lower-ranking noble, until the end of the 1520s, when he was either banished or went into self-exile.
[2] Some of his poems go so far as to give advice to the king and even criticise him and his favourite, Álvaro de Luna, the powerful Constable of Castile.
[3] In the historical context of an increasingly hostile anti-Jewish sentiment, some of the coplas he dedicated to the King showed a very negative attitude towards Jews and conversos and his criticism reached Álvaro de Luna, which may explain his abandoning the Court, and offering his services to Courts of Aragon and Navarre, where he was active from 1429.
[2] In fact, at that time, the Marquis of Santillana had written some very scathing verses, Dezir contra los aragoneses,[3] which became very popular,[2] criticising Aragon and Navarre, to which Juan de Dueñas replied immediately stating his political position in Coplas.... sobre razones que dezian algunos mançebos de Castilla,[3] and during the war between the crowns of Castile and Aragon (1429–1430), Dueñas actually confronted the Marquis in a skirmish on the border, with the Marquis having to flee to avoid capture.
[2] In his Coplas... al Señor Rey... suplicándole por tres dueñas" [Coplas... addressed to the King... imploring him on behalf of three Ladies], an allegory in which he narrates a dream he had after abandoning the King's court, three Ladies—Justice, Peace and Clemency, all dressed in mourning, explain to the dreamer that they are scorned at Court.