Born the youngest of three sons to an innkeeper in Paris, Joseph's brothers were sent to the borders to defend the French borders against Prussia while he was exempted due to his young age. Instead, Joseph became a drummer in a unit in Vendée. On 7 December 1793, Joseph was killed when his unit were ambushed by a group of royalist during an incident where they tried to steal horses.
Maximilien de Robespierre, a politician and a member of the Templar Order, seized the opportunity and used Joseph's death as a form of propaganda, proclaiming "Only the French have 13 year-old heroes."
The Assassin Arno Dorian helped transfer Bara's remains to the Panthéon. Later that month, the painter Jacques-Louis David completed a painting depicting Joseph, entitled The Death of Joseph Bara.