The final offensive on Paris by MacMahon's army began early in the morning on Sunday, 21 May. On the front line, soldiers learned from a sympathiser inside the walls that the National Guard had withdrawn from one section of the city wall at Point-du-Jour, and the fortifications were undefended.
An army engineer crossed the moat and inspected the empty fortifications, and immediately telegraphed the news to Marshal MacMahon, who was with Thiers at Fort Mont-Valérien.
MacMahon immediately gave orders, and two battalions passed through the fortifications without meeting anyone, and occupied the Porte de Saint-Cloud and the Porte de Versailles.
By four o'clock in the morning, sixty thousand soldiers had passed into the city and occupied Auteuil and Passy.

Once the fighting began inside Paris, the strong neighborhood loyalties that had been an advantage of the Commune became something of a disadvantage: instead of an overall planned defence, each "quartier" fought desperately for its survival, and each was overcome in turn.
The webs of narrow streets that made entire districts nearly impregnable in earlier Parisian revolutions had in the centre been replaced by wide boulevards during Haussmann's renovation of Paris.
The Versailles forces enjoyed a centralised command and had superior numbers.
They had learned the tactics of street fighting and simply tunnelled through the walls of houses to outflank the Communards' barricades.

The trial of Gustave Cluseret, the former commander, was still going on at the Commune when they received the message from General Dombrowski that the army was inside the city.
He asked for reinforcements and proposed an immediate counterattack. "
Remain calm," he wrote, "and everything will be saved.
We must not be defeated!".
When they had received this news, the members of the Commune executive returned to their deliberations on the fate of Cluseret, which continued until eight o'clock that evening.

The first reaction of many of the National Guard was to find someone to blame, and Dombrowski was the first to be accused.
Rumours circulated that he had accepted a million francs to give up the city.
He was deeply offended by the rumours.
They stopped when Dombrowski died two days later from wounds received on the barricades.
His last reported words were: "Do they still say I was a traitor?"
The final offensive on Paris by MacMahon's army began early in the morning on Sunday, 21 May. On the front line, soldiers learned from a sympathiser inside the walls that the National Guard had withdrawn from one section of the city wall at Point-du-Jour, and the fortifications were undefended. An army engineer crossed the moat and inspected the empty fortifications, and immediately telegraphed the news to Marshal MacMahon, who was with Thiers at Fort Mont-Valérien. MacMahon immediately gave orders, and two battalions passed through the fortifications without meeting anyone, and occupied the Porte de Saint-Cloud and the Porte de Versailles. By four o'clock in the morning, sixty thousand soldiers had passed into the city and occupied Auteuil and Passy.
Once the fighting began inside Paris, the strong neighborhood loyalties that had been an advantage of the Commune became something of a disadvantage: instead of an overall planned defence, each "quartier" fought desperately for its survival, and each was overcome in turn. The webs of narrow streets that made entire districts nearly impregnable in earlier Parisian revolutions had in the centre been replaced by wide boulevards during Haussmann's renovation of Paris. The Versailles forces enjoyed a centralised command and had superior numbers. They had learned the tactics of street fighting and simply tunnelled through the walls of houses to outflank the Communards' barricades.
The trial of Gustave Cluseret, the former commander, was still going on at the Commune when they received the message from General Dombrowski that the army was inside the city. He asked for reinforcements and proposed an immediate counterattack. "Remain calm," he wrote, "and everything will be saved. We must not be defeated!". When they had received this news, the members of the Commune executive returned to their deliberations on the fate of Cluseret, which continued until eight o'clock that evening.
The first reaction of many of the National Guard was to find someone to blame, and Dombrowski was the first to be accused. Rumours circulated that he had accepted a million francs to give up the city. He was deeply offended by the rumours. They stopped when Dombrowski died two days later from wounds received on the barricades. His last reported words were: "Do they still say I was a traitor?"
Paris Commune