A regent is “a person appointed to administer a state because the monarch is a minor, is absent or is incapacitated.”
Eleanor of Aragon was born on 1 February 1402 as the daughter of Ferdinand I of Aragon and Eleanor of Alburquerque. She lost her father at the age of 14, and he was succeeded by her brother Alfonso V. Her mother arranged for her to marry the future King Edward of Portugal, and the marriage took place on 22 September 1428. They would go on to have nine children, although four did not survive to adulthood.
Her husband succeeded as King of Portugal on 14 August 1433, and on the same day, their eldest son John died. As Queen of Portugal, Eleanor was quite unpopular. She was Queen for just five years as her husband died of the plague on 13 September 1438, while Eleanor was pregnant. In his will, he appointed her regent of Portugal, which was confirmed by the Portuguese Cortes. However, due to her unpopularity, the confirmation of the regency caused a riot in Lisbon. The people preferred to see Edward’s brother Infante Peter, Duke of Coimbra as the regent. Negotiations dragged out for several months, during which she gave birth to her daughter Joan, and she lost her eldest daughter Philippa to tuberculosis.
The Cortes eventually appointed Infante Peter as the sole regent. Eleanor was none too pleased with that, but she was exiled to Castile in December 1440, where she also fell ill. She died of a respiratory illness on 19 February 1445.