Step 12 of 20 · Act 2 · What changed
The republic and the death of the king
September 1792 – January 1793
France became a republic and executed its king — a point of no return that deepened the war and closed off any compromise.
With the monarchy suspended, the mood in Paris was dark and fearful. In early September 1792, as enemy armies advanced, panic boiled over into the September MassacresThe killing of over a thousand prisoners by Paris crowds in September 1792, amid panic about invasion and betrayal., in which crowds killed more than a thousand prisoners suspected of being traitors. The Revolution's promise of rights now sat beside terrible violence.
Later that month a newly elected assembly, the National ConventionThe assembly, elected in 1792, that declared the republic and put the king on trial., met and took a historic step: it abolished the monarchy and declared France a republicA state with no monarch, governed in the name of the people. — a state with no king, governed in the name of the people.
Then came the greatest break of all. The Convention put Louis XVI on trial for betraying the nation. The debate was fierce, and the final vote was close. He was condemned to death and executed by guillotine on 21 January 1793.
The killing of a king — regicideThe killing of a king — here, the execution of Louis XVI in January 1793. — shocked the courts of Europe and hardened the war against France. It also destroyed any path back to compromise. There could be no return to a constitutional monarchy now; the Revolution had to succeed as a republic, or fall.
What matters here
The Convention abolished the monarchy and, after a close vote, executed Louis XVI. Regicide united Europe against France and made a return to monarchy impossible — the Revolution now had to win as a republic.

Historical source
A point of no return, printed at the time: the execution of the king before the assembled crowd.
The execution of Louis XVI, 21 January 1793 — Contemporary engraving, 1793.
Public domain · Wikimedia Commons
Misconception check
“Everyone in France agreed that the king should be put to death.”