Alfonso de Castilla y Molina was a Spanish noble in the service of the Kingdom of Castile.
Background
Alfonso was the son of King Sancho IV of Castile and his wife the queen, María de Molina. His paternal grandparents were Alfonso X of Castile and his wife, Violant of Hungary, herself the daughter of James I of Aragon. His maternal grandparents were the infante Alfonso de Molina, son of Alfonso IX of Leon and his third wife, Mayor Alfonso de Meneses.
He was the brother of Ferdinand IV of Castile Pedro de Castilla y Molina, Felipe, Enrique de Castilla y Molina, Beatriz and Isabella, amongst others
Career
Alfonso was born in Valladolid in 1286. Towards the end of 1291, King Sancho IV of Castile and Juan Núñez I de Lara, head of the House of Lara, in the effort to forge a political alliance, decided to betroth Alfonso to Juana Núñez de Lara, Juan Núñez I"s eldest daughter. He was 5 years old at the time.
Alfonso did not survive the year however and the subsequent political alliance fell apart as Juan Núñez I went into self-imposed exile and rebellion against Sancho IV. Alfonso de Castilla y Molina died in Valladolid in 1291 at five years of age.
In the Museo de Valladolid, located in the Palacio de Fabio Nelli. On display is the actual sepulcher and the clothes that the infante was buried in.