Ouro Preto is most famous in Brazil as the birthplace of the Inconfidência Mineira (the Mineira Betrayal), the first attempt to free Brazil from the Portuguese. Inspired by the French Revolution, and heartily sick of the heavy taxes levied by a bankrupt Portugal, a group of twelve prominent town citizens led by Joaquim José da Silva Xavier began in 1789 to discuss organizing a rebellion. Xavier was a dentist, known to everyone as Tiradentes, “teeth-puller”. Another of the conspirators was Tomas Gonzaga, whose hopeless love poems to the beautiful Marília Dirceu, promised by her family to another, made the couple into the Brazilian equivalent of Romeo and Juliet: “When you appear at dawn, all rumpled/like a badly wrapped parcel, no ribbons or flowers/how Nature shines, how much lovelier you seem.”

The conspiracy proved a fiasco and all were betrayed and arrested before any uprising was organized. The leaders were condemned to hang, but the Portuguese, realizing they could ill afford to offend the inhabitants of a state whose taxes kept them afloat, arranged a royal reprieve, commuting the sentence to exile in Angola and Mozambique. Unfortunately the messenger arrived two days too late to save Tiradentes, marked as the first to die. He was hanged where the column now stands in the square that bears his name, his head stuck on a post and his limbs despatched to the other mining towns to serve as a warning.