 He was born in 1548 in what later became the city of Zacatecas and was raised by Franciscan friars in the city's monastery.Caldera entered the Chichimeca War in 1571 or 1572 at the age of 24 or 25 as a common soldier with the help of his brother-in-law Hernàn Gonzales.He obtained the rank of captain before 1580.