Joaquim Silvério dos Reis Montenegro Leiria Grutes (1756–1819) was a conspirator who betrayed the Inconfidência Mineira in exchange for having his taxes waived.
In the early 18th century, the Portuguese crown began to institute a series of taxes and levies around all mining activity in its Brazilian colony.
With the depletion of several gold mines, especially in Vila Rica (present day Ouro Preto), the local population lived in fear of an even more violent derrama, which in part triggered a group of "inconfidentes", conspirators against the Portuguese, to start planning a revolt in time for the derrama of 1789. Notable inconfidentes included Lt.-Colonel Francisco de Paula Freire de Andrade and the poets Cláudio Manuel da Costa, Tomás António Gonzaga, Alvarenga Peixoto and Joaquim José da Silva Xavier, who would later be best known as Tiradentes.
Joaquim became aware of the inconfidentes' intent to revolt and wrote a plea letter on 11 April 1789, to the Governor of Minas Gerais, the Viscount of Barbacena, essentially alerting the colonial authorities to the existence of a movement in Vila Rica which intended to proclaim a Republic in Brazil and free it from Portugal.
[1][4] As compensation for his plea, Joaquim issued a series of demands: a prize in gold, to be forgiven of his fiscal debts, to be named Treasurer of the provinces of Minas Gerais, Goias and Rio de Janeiro, a private mansion, a lifetime pension, the title of Fidalgo, the honour and uniform of the Portuguese Military Order of Christ and a meeting in Lisboa with the Prince Regent Dom João.