House of Lara
He was the son of Juan Núñez I de Lara, head of the House of Lara, and his first wife, Teresa Álvarez de Azagra, Lady of Albarracín. His paternal grandparents were Nuño González de Lara "el Bueno", head of the House of Lara, and his wife Teresa Alfonso; his maternal grandparents were Álvaro Pérez de Azagra, Lord of Albarracín, and his wife, Inés, illegitimate daughter of King Theobald I of Navarre. His half-brothers, born to his father's second wife, were Juan Núñez II de Lara, head of the House of Lara; Nuño González de Lara; Teresa Núñez de Lara y Haro, and Juana Núñez de Lara.