Through a royal letter issued on 2 October 1377, her father granted her the Lordship of Viseu, Celorico, Linhares and Algodres.
She left to the Royal Court of King Henry II of Castile where she lived while waiting for an appropriate age to get married. They finally married in November 1377[3] in the city of Burgos. This marriage gave rise to the Noronha family, still represented in several aristocratic houses, both in Portugal and in Spain.
João de Noronha,[5] participated in the siege of Balaguer and was knighted by InfanteDuarte in the siege of Ceuta where he was injured. He died from his wounds shortly afterwards without having left any offspring.
Isabella eventually returned to her native Portugal where her uncle, King John I of Portugal, gave her a warm welcome and protection, both to her and to her children.
Menéndez Pidal de Navascués, Faustino (1982). Instituto Luis de Salazar y Castro (ed.). Heráldica medieval española: la Casa Real de León y Castilla (in Spanish). Vol. I. Madrid: Hidalguía. ISBN8400051505.
Sousa, António Caetano de (1946). História Genealógica da Casa Real Portuguesa (in Portuguese). Vol. I. Coimbra: Atlântida-Livraria Editora, Lda. OCLC829426236.
"Nobreza de Portugal e Brasil" – Vol. II, pages 234/235. Published by Zairol Lda., Lisbon 1989.