Ercole Consalvi was born in Rome in 1757. He was educated at a school operated there by Cardinal York, a direct descendent of the Stuarts whom some Catholics recognized as King Henry IX of England. He became a favorite of the Cardinal's and was helped by him to obtain high office in the Roman curia while still a young man.

After the French invaded Italy in 1798, Consalvi was jailed, but he later escaped and joined Pope Pius VI in exile. An able diplomat, he played an important role in the conclave that elected Pius VII as Pius VI's successor.

The new pope named him Secretary of State, and in this capacity he negotiated a concordat with Napoleon that greatly improved the position of the Church in France. He also reformed the administration of Rome and to some extent modernized the city.

After the fall of Napoleon, he represented the Pope at the Congress of Vienna and was able to convince the victorious powers to restore the Papal States almost entirely. For the remainder of the pontificate of Pius VII, Consalvi was the virtual ruler of Rome, and his government was characterized by good sense, moderation and concern for the poor. He retired when Pius died in 1823, and himself died the following year. Although a consumate diplomat and man of the world, Consalvi was both honest and pious and has been called "one of the purest glories of the Church of Rome" (Schaeffer).