Xavier was a Brazilian revolutionary who, as a founder of the Inconfidência Mineira movement, fought for Brazilian independence and freedom from Portuguese colonial power. 

At the time, Portugal was imposing onerous tax burdens on the Brazilians, as they tried to maintain income from the colony despite declining levels of gold being mined. 

Tiradentes hatched a plan to take to the streets and declare independence on a day when taxes were due. The plan was betrayed and the rebels were arrested in February 1789. 

During the subsequent trial, Tiradentes took full responsibility for the insurrection plot and executed by hanging on April 21st 1792. His body was quartered and his head displayed as a warning to other revolutionaries. 

Xavier was a dentist by trade. This holiday gets its name from “tiradentes” meaning “tooth-puller”, which was a nickname adopted during his trial. 

His martyrdom led to Tiradentes becoming considered a national hero by the republicans of the 19th century, and his liberal ideas continued to influence Brazilian thinking until its independence, nearly 100 years after his death, in 1882. 

The anniversary of his death (April 21st) became a national holiday after the republic was proclaimed in 1889.