Isabella, Princess of Asturias (2 October 1470 – 23 August 1498) was the eldest daughter and heir presumptive of King Ferdinand II of Aragon and Queen Isabella I of Castile. She was Queen of Portugal as the wife of King Manuel I from 30 September 1497 until her death the following year. Early life Isabelle was the eldest child of Ferdinand II of Aragon and Isabella I of Castile. Born during the reign of her uncle, Henry IV of Castile, the early years of her life were defined by the tension between him and her mother, as her uncle would not forgive her mother for marrying Ferdinand without his permission. Upon the death of Henry IV in 1474, Isabella's mother claimed the throne of Castile, and the young Isabella was swiftly sworn as the heir presumptive to the throne. The early years of the reign of Isabella I were spent embroiled in a war of succession, as Henry IV had not specifically named a successor. A struggle ensued between Isabella I and her niece Joanna, who was known as "la Beltraneja" due to the rumors that she was the illegitimate child of Henry IV's queen Joan of Portugal and his favourite, Beltrán de la Cueva, 1st Duke of Alburquerque. Afonso V of Portugal, who was Henry IV's brother-in-law and young Joanna's uncle, intervened on Joanna's behalf and Ferdinand and Isabella were forced into a war with Portugal. During the war, young Isabella witnessed some of the chaos for herself. While her parents were fighting the Portuguese, the princess was left in Segovia while the city was placed under the control of Andrés de Cabrera and his wife Beatriz de Bobadilla. The city's residents, unhappy with this new administration, rose up and seized control of the city. The then-seven-year-old princess was trapped in a tower of the Alcázar for some time until her mother returned to Segovia and took control of the situation. The war ended in 1479 with the Treaty of Alcáçovas. Among the terms were the provision that Princess Isabella would marry the grandson of Afonso V, Afonso, who was five years younger than the princess. The treaty also provided that Ferdinand and Isabella would pay a large dowry for their daughter and that the princess would reside in Portugal as a guarantee that her parents would abide by the treaty terms. In 1480, Prince Afonso went to live