Alonso Manso was born in Becerril de Campos, Spain[2] and studied theology at the University of Salamanca.

[2] On August 8, 1511, Pope Julius II created three dioceses in the New World, two in Hispaniola (Santo Domingo and Concepción de la Vega) and one in Puerto Rico (San Juan), and Manso was appointed bishop of the diocese of Puerto Rico.

In 1519, at the request of Bishop Manso the diocese of Puerto Rico was expanded to cover all the Leeward Islands.

Aside from establishing the first advanced studies school he performed the first episcopal consecration in the New World when in 1529, at the Cathedral of San Juan, he consecrated Sebastián Ramírez de Fuenleal, elected bishop of Santo Domingo.

Bishop Manso died in San Juan, Puerto Rico, in 1539 at the age of 79.