The French monarchy was abolished for the first (but not the last) time on this day in 1792. King Louis XVI had been intent on maintaining a firm grip on the state and not giving up power to elected officials. He would not succeed.
The king had conceded some powers reluctantly, but then tried to flee the country to seek assistance from other monarchies who were not too keen on seeing nations rise up against their royal leaders. He got caught, and after some more flip-flopping, the new National Convention (the equivalent of Congress) was fed up. The legislators were middle-class folks, and as conflict with the king grew, their view of the monarchy had gone from disliking it to wanting it to be destroyed entirely.
The vote was unanimous: France was now a republic. Four months later, the king was executed.