After being imprisoned by the sans-culottes in Paris, he was trialed for encouraging other countries against the revolution. A month later, he was trialed for execution.
The trial was held on December 3, 1792. King Louis XVI was trialed before the National Convention.
Louis XVI was charged with 33 total charges which included bribing officials, vetoing decrees made by the National Assembly, and causing Frenchman blood to flow.
The defense, Raymond Deseze, argued that the charges are invalid since the king can't be persecuted based on the Constitution of 1791 and attacked the National Convention acting as judge and jury. He painted the king in a good light.
There wer 721 voters in total with no one voting no in killing the king. 361 voted for execution with no conditions, 319 voted for imprisonment until the end of the war followed by banishment. The rest voted for execution with certain terms.
Louis XVI was executed in the Place de la Revolution on January 21, 1793. The crowd cheered after with an artillery salute and shouted, "Vive la Nation! Vive la Republique!"