The imposing painting of King Pedro IV that lives, like a tutelary icon, in the reading room of the Municipal Public Library of Porto, is the vehicle for an approach to discovering its author and a personality that overflows with the city's culture: João Baptista Ribeiro.

Born in 1790 in Vila Real, but settled in Porto as a young man to study drawing, João Baptista Ribeiro can be considered the founding director of the Porto Museum: in the midst of the Siege, he was commissioned by King Pedro IV to organise the Museu Portuense (or Museum of Paintings and Prints) and to coordinate the collection of spoils from the closed monasteries and houses confiscated from the absolutist rebels; and in 1836 he was appointed director by decree of King Maria II. He left the Museu Portuense in 1839, when it was already housed in the Convento de Santo António (it opened to the public the following year).

During the siege, he maintained close and regular contact with King Pedro and was a regular presence at the palace to execute the portrait of the monarch, from whom he received a lithographic printing press.

A brilliant drawing student of the most important Porto masters of his time, he was a professor and director of Porto's three higher education academies - the Royal Academy of Marine and Commerce, the Academia Portuense de Belas-Artes and the Academia Politécnica do Porto - painter, museologist and pioneer of lithography and the daguerreotype.

He was responsible for a veritable cultural seedbed in Porto, in academies, museums and art galleries. He died in 1868 and was buried in the Prado do Repouso cemetery.