Its history has its beginning on September 6, 1571 when the Spanish Adelantado, Miguel Lopez de Legaspi, allotted the community to a Spaniard named Juan Gutierrez Cortes as his ""encomienda"". At that time, the community was still composed of small clusters of settlements along the banks of a big river which later became known as the Bago River. The ""encomiendero"", since then, administered to the spiritual and socio-economic needs of the natives in the settlements until June, 1578; however, a year before that, this community was placed under the evangelical visitations of Father Geronimo Marin, an Augustinian priest who had taken charge of the Christianization of the natives of Binalbagan since the year 1572. Father Marin, upon his arrival in the community, celebrated the feast of St. John the Baptist, who would later be accepted as the patron saint of the place. Following the traditions and practices of the Spanish missionaries and historians in recording the founding of a ""pueblo"" or town that usually coincides with the feast day of a saint and since the feast day of St. John the Baptist, falls on June 24 of each year, it follows thereof that Bago was founded on June 24, 1575. History only records 1575 as the year when Bago was founded so that the exact month and day can only be deduced from such traditional practices of the Spaniards. Manila, Cebu and Binalbagan also predicted the dates of their founding on the same historical situations; hence, the logical conclusion is that Bago City was officially founded on the month, day and year heretofore mentioned.