 Martín Alfonso de León

Martín Alfonso de León (c. 1220before April 1272) was an illegitimate son of Alfonso IX of León by Teresa Gil de Soverosa, a Portuguese noble woman, daughter of Gil Vasques de Soverosa and María Aires de Fornelos, also mistress of King Sancho I of Portugal with whom she had a son and daughter.The relationship between King Alfonso IX and Teresa began in 1218 and lasted until the king's death.