 Argüelles was born in 1566 in the Spanish settlement of San Agustín, Spanish Florida.Martín's parents were Martín de Argüelles (Sr.) and Leonor Morales.His father, Martín Argüelles Sr., an Asturian "hidalgo", was one of the expeditioners who came to New Spain in the New World with Captain General Pedro Menéndez de Avilés in 1565.