There was a palace here before this one. In 1680 the Portuguese put up a Casa de Residência - a residence house - for governors coming to inspect the Captaincy of Pará. It aged badly. By 1754, in the Pombaline years, Friar Miguel de Bulhões, standing in for Governor Mendonça Furtado, ordered an inspection that came back with an unhappy verdict: the building needed propping to stop it collapsing. Three years later the administration gave up and moved into a rented house.

In 1759 Governor Manuel Bernardo de Mello e Castro asked Lisbon for a technical judgment, and the Kingdom sent a commission - the architect Antonio Landi with the engineers Galluzie and Manuel Mendes. They confirmed the ruin and recommended demolition, salvaging whatever tiles and timber were worth keeping. Colonial administration in the Amazon ran on exchanges like this. A wall cracks in Belém, and the answer arrives from six thousand kilometres away, months later, in writing.

Work on the replacement began in 1768 under a master mason named Jerônimo da Silva. To get the footprint the design wanted, the government bought three adjoining lots. The building was finished in November 1771 and occupied the following year by João Pereira Caldas, the Portuguese colonial administrator who inaugurated it as the palace of the governors of the State of Grão-Pará and Maranhão.

Landi gave it a classical Italian face, working from the neo-Palladian ideas he had carried out of Bologna, and the result is a piece of European academic architecture set down on the bank of a tropical bay. A rumour has followed it ever since: that it was really built for King Joseph I of Portugal, in case the royal family ever had to move the court to the colonies. No document supports this. The palace is grand enough that people kept saying it anyway, and it carries a second nickname - the King's Palace - to show for it.

The revolt that took this building in 1835 was not a palace coup. The Cabanagem drew on the people the province counted least: the poor of the Amazon, Indigenous and Black and mixed-race, many of them living in the riverside cabanas that gave the movement its name. Between 1835 and 1840 they fought the imperial government to a standstill and, for a time, ran Grão-Pará themselves. Estimates of the dead run into the tens of thousands.

Antônio Vinagre's fighters left Belém in 1837 and carried the war into the interior for three more years. The palace went back to the governors. Nothing in the architecture records what happened here on January 6 - the building was designed to express a very different kind of authority, and it went on expressing it. But for two years the grandest room in Portuguese Amazonia belonged to people who had never been meant to enter it.

The palace stayed in government use long after the empire ended, which is why it is also called the Palácio do Governo. The Museu do Estado do Pará was created in 1981; in 1994, under Governor Jader Barbalho, the building was converted to house it, and the museum has been here since. Its programme runs from visual-arts exhibitions to video-mapping projected onto the facade after dark, a use for a neoclassical elevation that Landi would have struggled to picture.

IPHAN, the national heritage institute, protects the building. It stands on Avenida Portugal in Cidade Velha, beside the state's judicial and legislative headquarters, inside a dense block of listed structures: the Ver-o-Peso Dock, Clock Square, Dom Pedro II Square, the Antônio Lemos Palace, the Baron of Guajará Manor House. Belém keeps a remarkable amount of its history in a very small area, and most of it is still in use.