Eleanor of Viseu (died 1525)

Dona Eleanor of Avis, also known as Leonor de Lencastre or Eleanor of Viseu, was a Portuguese infanta (princess) and queen consort of Portugal. She was wife of King John II of Portugal and sister to King Manuel I of Portugal. Eleanor is one of Portugal's more famous queen consorts and is best known as the founder of the Santa Casa da Misericórdia, a charitable organization operating since 1498.