Isabel of Portugal, Lady of Viseu

Isabella of Portugal (1364–1395) was the natural daughter of King Ferdinand I of Portugal, from unknown mother.

Before 1386 she was betrothed to João Afonso Telo de Menezes, 1st Count of Viana (do Alentejo), son of the powerful João Afonso Telo, 4th Count of Barcelos. However, this project was abandoned or dissolved.

She married Alfonso Enríquez, Count of Gijón and Noreña, natural son of King Henry II of Castile. Her marriage was one of the clauses of the Treaty of Santarém, signed in 1373, between Portugal and Castile.

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 1377 in the city of Burgos. This marriage gave rise to the Noronha family, still represented in several houses, both in Portugal and in Spain.

The couple had seven children:

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.

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