- (c. 1340-1390) Illegitimate son of Don Juan Manuel and Inés de Castañeda.
- Half-brother of Constanza Manuel de Villena, wife of Pedro I of Portugal before he became king.
- He served the Portuguese monarchs Pedro and Fernando and received many titles including Count of Seia and of Sintra and Lord of Cascais. He fought for King Fernando of Portugal during the wars he waged with Castile. [Fernando, ch. 78]
- Brother-in-law to Queen Leonor Teles. According to Fernão Lopes, he was made Count of Seia thanks to the influence of his royal sister-in-law.
- Curator to Princess Beatriz, daughter of King Fernando and Queen Leonor Teles, and witness at the princess's betrothal to Don Fadrique, Count of Benavente, son of King Enrique II of Castile (1376). [Fernando, ch. 96]
- After King Fernando's death, however, he sided with the Castilian faction [ João1, ch. 67]. As a consequence, João I of Portugal deprived him of his estates in Portugal, whereas Juan I of Castile rewarded him as Lord of Montereal, Meneses and Belmonte.
Hanrrique Manuell