In 1581, Domingo de Salazar, OP, the first Bishop of Manila, decreed the establishment of a seminary to prepare native men for the priesthood and ecclesiastical dignities.

He ordered all archbishops and bishops of the Indies to found and support seminaries decreed by the Council of Trent for the formation of native clergy.

Since the Philippines was then under the Patronato Real system, on April 28, 1702, King Philip V of Spain ordered the establishment of a seminary in Manila for eight seminarians.

However, this plan was modified by Giovanni Battista Sidoti, an Italian priest accompanying Archbishop Charles Thomas Maillard de Tournon, papal legate to Peking, on the way to China.

He worked for the erection in Manila of an Asian regional seminary for seventy-two seminarians of the Far East, with the approval of Archbishop Diego Camacho y Ávila.

Having learned of the development, the King ordered the closure and demolition of the seminary building, the execution of his original plan, and the transfer of Archbishop Camacho to Mexico.

The impetus for a review of how the Patronato Real administered the seminary came when Bishop Miguel Lino de Espeleta of Cebu became Acting Governor-General of the Philippines from 1759 to 1761.

As a result, reforms were instituted, and the magnificent buildings of the expelled Jesuits, the Church and Colegio de San Ignacio were assigned to the diocesan seminary.

The Congregation of the Mission (CM), familiarly known as Vincentian Fathers, took charge over the seminary on August 2, 1862, under the patronage of Queen Isabella II and with the support of Archbishop Gregorio Melitón Martínez de Santa Cruz.

In 1951, he blessed the cornerstone for the new building of San Carlos Seminary in Guadalupe Viejo village along Highway 54 (now Epifanio de los Santos Avenue or EDSA).

On January 24, 1953, Cardinal Norman Thomas Gilroy, Archbishop of Sydney and papal legate to the First Plenary Council of the Philippines, blessed the new building.

The new seminary building housed both major and minor seminarians of the Archdiocese of Manila (which then also covered Rizal, Cavite and Bulacan and Laguna).

In 1951, the Congregation of the Immaculate Heart of Mary (CICM, known as the Belgian or Scheut Fathers) had been tasked by Rome with the formation of seminarians in Lipa, where Bishop Rufino J. Santos (later Archbishop of Manila in 1953 and the first Filipino cardinal in 1960) was the diocesan administrator.

It was located a block away from San Carlos Seminary in the direction of the Pasig River, near the present day Guadalupe MRT station.

In 1973, Cardinal Santos turned over the seminary administration from the CICM Fathers to the diocesan priests led by Oscar V. Cruz, who later became Auxiliary Bishop of Manila in 1976.

In that same year, the two-winged edifice for the Holy Apostles Senior Seminary (HASS) and the San Lorenzo Ruiz Lay Formation Center (or LayForce) was constructed.

On March 13, 1995, the cornerstone of Holy Apostles Senior Seminary was laid to give way to the full-swing formation of the laity at the Layforce Building.

[2] Being the only diocesan-run seminary in Metro Manila with a dual status of house of formation and house of studies (offering civil degrees in theology and philosophy, recognized and accredited by the Commission on Higher Education as with other colleges and universities), San Carlos Seminary provides updated holistic priestly formation for the dioceses of Metro Manila, as well as in other parts of the country and abroad, for as long as seminarians are recommended by their respective local ordinary.