The monument is located at the center of Plaza Roma in Manila, Philippines. It was erected in gratitude to King Charles IV for the introduction of the smallpox vaccine in the Philippines in 1805.
The statue was placed on a marble pedestal facing Manila Cathedral and dedicated in 1824. In1886, a fountain was built around the base of the monument.
In the 1960s, the monument was replaced with a monument dedicated to the Gomburza, three Filipino priests who were executed for campaigning for equal rights with Spanish friars. The original Charles IV monument was re-installed in the plaza in 1981 as ordered by President Ferdinand Marcos.