[2] In 1560, he arrived in New Spain to be consecrated[4] but was instead appointed on 5 December 1561 during the papacy of Pope Pius IV as Bishop of Cartagena[2] and not consecrated bishop until April 1564 by Juan de los Barrios, Archbishop of Santafé en Nueva Granada.
[2] Soon after his consecration, tensions rose with the then governor, Juan del Busto, over a free mulatto woman who had been enslaved and fled to the bishop for sanctuary to which he granted.
[3] The situation was also aggravated by the priestly community which had refused to absolve any encomiendos (settlers) of their sins via confession until they returned property stolen from the Indians; a stance the bishop supported.
[3] The situation soon escalated with the Indian population refusing to work and instead fleeing to the churches for sanctuary and the governor and his successor, Martin, violently removed them by force.
[3] However, the conflict so exhausted Simancas that he resigned without license[4] in 1569 and returned to Spain[3] where he died in 1570.