Henry III of Castile (4 October 1379 – 25 December 1406), called the Suffering due to his ill health (Spanish: Enrique el Doliente, Galician: Henrique o Doente), was the son of John I and Eleanor of Aragon.

Despite his nickname, King Henry III engaged in a vigorous foreign policy and manoeuvres during the first few years of the 15th century.

Henry III was supported by the aristocracy and displaced their most powerful relatives (such as Alfonso Enríquez and his aunt, Eleanor of Castile, Queen of Navarre).

He repealed privileges granted by his predecessors at the Court of Castile, such as the alcabala (a heavy sales tax) and the right to attend the council.

In 1396, he deflected a Portuguese invasion with an attack on Badajoz, finally signing a peace treaty with his brother-in-law, King John I of Portugal, on 15 August 1402.

He restarted the conflict against the kingdom of Granada, winning a victory at the Battle of Collejares, near Úbeda, which freed the town in 1406.

In 1406, King Henry built a pavilion (hunting lodge) on Mount El Pardo because of abundant game there.

The lodge would later be transformed into the Royal Palace of El Pardo by Charles V, Holy Roman Emperor, who would rule as King of Spain.

King Henry III died in the city of Toledo on 25 December 1406, while preparing a campaign against the Emirate of Granada.

Henry appears clothed in a Franciscan habit, although his hands are holding his sword in his girdle, which runs parallel to the Cordón de San Francisco.