1) Isabella was born in 1451 in Madrigal de las Altas Torres, Spain to King John II of Castile and Isabella of Portugal. As a princess, her education focused on her role as a wife and mother rather than a ruler.
2) After her father's death when she was 3, Isabella was sent to live with her depressed mother and brother Alfonso in gloomy conditions, with little money. Her brother Henry IV became King of Castile.
3) Henry took Isabella and Alfonso away from their mother, who descended into madness, in order to control and educate them at his court in Segovia.