On January 24, 1571 , feast of St. John the Baptist, the Spanish conquistador Miguel Lopez de Legaspi founded the city of Manila . He earlier took possession of Maynilad, the native settlement of Rajah Matanda and Rajah Sulayman on May 19, 1571 and firmly established Spanish authority in the newly conquered and untrammeled turf. The historic day happened to be the feast of Santa Potenciana and to honor her, she was made patroness of the new territory. Armed with the Spanish sword and the Cross, Legaspi, in his role as conquistador, apportioned a parcel of land for the church of the new settlement under the patronage of La Purisima Inmaculada Concepcion.
The Church of Manila was established by the secular Juan de Vivero who had the honor of baptizing Rajah Matanda. Vivero first arrived in these shores in 1566 as chaplain of the nao or galleon of San Geronimo which had come to support the Spanish colonization of the newly discovered islands. He was given the special privilege and sole faculty by the Archbishop of Miexico to establish the spiritual administration of the new Philippine colony. Later, Vivero would become the first vicar-general and the first ecclesiastical judge of Manila .
The Church of Our Lady of the Immaculate Conception administered the religious affairs of Manila until such time it became a parish and Manila was created into a diocese. It was a simple structure of nipa and bamboo, materials which were readily available during that time. It had for its first parish priest the secular Juan de Villanueva. The other religious who became the pillars of this parish were Juan de Vivaneta and Nicolas Riccio.
This church was also witness to the events that would threaten the city and its residents. On November 30, 1574 , the feast of St. Andrew the Apostle, the Spanish forces were able to quell Limahong’s invasion. Because of such fortunate turn of events, the holy apostle was made patron saint of Manila . The victory was celebrated with fireworks and a Mass with sermon was held in the Church of Our Lady of the Immaculate Conception in Manila .