Duarte I of Portugal
Duarte I ruled Portugal for only five years, from 1433 to 1438, and is remembered as much for what he wrote as for what he did. Born in Viseu in 1391, the eldest surviving son of João I and Philippa of Lancaster, he was educated exceptionally well and was associated with government from his teens, effectively running the administration for years before his father died. He is called the Philosopher King or the Eloquent. He wrote O Leal Conselheiro, a treatise on ethics and the management of the emotions that includes an unusually direct account of his own depression, and Livro da Ensinança de Bem Cavalgar Toda Sela, a manual on horsemanship. Both are significant works of early Portuguese prose. He summoned the cortes frequently and passed the Lei Mental in 1434, a law providing that crown grants of land reverted to the crown unless inherited by a legitimate male heir in the direct line — a device that slowed the permanent alienation of royal property to the nobility. He supported his brother Henry's voyages, and it was during his reign that Gil Eanes rounded Cape Bojador in 1434, passing the point beyond which sailors had believed return impossible and opening the West African coast. Against the advice of his brother Pedro he authorised the expedition to Tangier in 1437. It was a disaster: the army was surrounded and forced to negotiate a withdrawal, leaving his youngest brother Fernando as a hostage against the return of Ceuta. The cortes refused to surrender Ceuta, and Fernando died in captivity in 1443. Duarte died of plague in September 1438, reportedly broken by it.
- Lived: 1391 CE – 1438 CE
- Nationality: Portuguese
- Roles: king, head_of_state
