Isabel and Fernando had four children: Even at a young age, John II of Portugal was not popular among the peers of the kingdom since he was immune to external influence and appeared to despise intrigue.

The nobles (including particularly Isabella's husband, the Duke of Braganza) were afraid of his future policies as king.

Letters of complaint and pleas to intervene were exchanged between the Duke of Braganza and Queen Isabella I of Castile.

Many other members of Isabel's family were murdered including her elder brother Diogo, Duke of Viseu.

At first, Leanor was made heiress but because she was Dowager Queen and had no surviving children, the post as heiress was passed to Isabel, who in turn passed it to her eldest son Jaime, who was heir from 1495 until 1498 when Manuel's son Miguel da Paz, Prince of Portugal was born.