Медина-дель-Кампо
Montalvo was born in Medina del Campo in the Province of Valladolid, Spain. He came from an influential family, belonging to the Pollino lineage, one of the seven who dominated Medina's council policy. This lineage came from Martín Gutiérrez de Montalvo, VIII lord of Botalorno. At one time Montalvo had the title "Alderman of Medina del Campo" and was clerk of the land of the surrounding town. In 1482 he was part of a contingent sent from Medina del Campo to guard Alhama in the Province of Granada, which had recently been captured from the Moors.