On August 1 Montcalm advanced by land and water. He sent Levis by land with 3,000 men to cut Fort William Henry off from Fort Edward, while he went himself, with the rest of his army, by water in boats and canoes. The next day they met at a little bay quite close to the fort. On the 3rd the final advance was made. The French canoes formed lines stretching right across the lake. While the artillery was being landed in a cove out of reach of the guns of the fort Levis was having a lively skirmish with the British, who were trying to drive in their cattle and save their tents. About 500 of them held the fort, and 1,700 were in the entrenched camp some way beyond.

Montcalm sent in a summons to surrender. But old Colonel Monro replied that he was ready to fight. On the 4th and 5th the French batteries rose as if by magic. But the Indians, not used to the delay and the careful preparation which a siege involves, soon grew angry and impatient, and swarmed all over the French lines, asking why they were ordered here and there and treated like slaves, why their advice had not been sought, and why the big guns were not being fired. Montcalm had been counselled to humour them as much as possible and on no account whatever to offend them. Their help was needed, and the British were quite ready to win them over to their own side if possible. Accordingly, on the afternoon of the 5th, Montcalm held a grand 'pow-wow' with the savages. He told them that the French had to be slow at first, but that the very next day the big guns would begin to fire, and that they would all be in the fight together. The fort was timbered and made a good target. The Indians greeted the first roar of the siege guns with yells of delight; and when they saw shells bursting and scattering earth and timbers in all directions they shrieked and whooped so loudly that their savage voices woke almost as many wild echoes along those beautiful shores as the thunder of the guns themselves.

Presently a man came in to the French camp with a letter addressed to Monro, which the Indians had found concealed in a hollow bullet on a British messenger whom they had killed. This letter was from Monro's superior officer, General Webb, fourteen miles distant at Fort Edward. He advised Monro to make the best terms possible with Montcalm, as he did not feel strong enough to relieve Fort William Henry. Montcalm stopped his batteries and sent the letter in to Monro by Bougainville, with his compliments. But Monro, while thanking him for his courtesy, still said he should hold out to the last.

Montcalm now decided to bring matters to a head at once. As yet his batteries were too far off to be effective, and between them and the fort lay first a marsh and then a little hill. By sheer hard work the French made a road for their cannon across the marsh; and Monro saw, to his horror, that Montcalm's new batteries were rising, in spite of the British fire, right opposite the fort, on top of the little hill, and only two hundred and fifty yards away.

Monro knew he was lost. Smallpox was raging in the fort. Webb would not move. Montcalm was able to knock the whole place to pieces and destroy the garrison. On the 9th the white flag went up. Montcalm granted the honours of war. The British were to march off the next morning to Fort Edward, carrying their arms, and under escort of a body of French regulars. Every precaution was taken to keep the Indians from committing any outrage. Montcalm assembled them, told them the terms, and persuaded them to promise obedience. He took care to keep all strong drink out of their way, and asked Monro to destroy all the liquor in the British fort and camp.

In spite of these precautions a dire tragedy followed. While the garrison were marching out of the fort towards their own camp, some Indians climbed in without being seen and began to scalp the sick and wounded who were left behind in charge of the French. The French guard, hearing cries, rushed in and stopped the savages by force. The British were partly to blame for this first outrage: they had not poured out the rum, and the Indians had stolen enough to make them drunk. Montcalm came down himself, at the first alarm, and did his utmost. He seized and destroyed all the liquor; and he arranged with two chiefs from each tribe to be ready to start in the morning with the armed British and their armed escort. He went back to his tent only at nine o'clock, when everything was quiet.

Much worse things happened the next morning. The British, who had some women and children with them, and who still kept a good deal of rum in their canteens, began to stir much earlier than had been arranged. The French escort had not arrived when the British column began to straggle out on the road to Fort Edward. When the march began the scattered column was two or three times as long as it ought to have been. Meanwhile a savage enemy was on the alert. Before daylight the Abnakis of Acadia, who hated the British most of all, had slunk off unseen to prepare an ambush for the first stragglers they could find. Other Indians, who had appeared later, had begged for rum from the British, who had given it in the hope that, in this way, they might be got rid of. Suddenly, a war-whoop was raised, a wild rush on the British followed, and a savage massacre began. The British column, long and straggling already, broke up, and the French escort could defend only those who kept together. At the first news Montcalm ordered out another guard, and himself rushed with all his staff officers to the scene of outrage. They ran every risk to save their prisoners from massacre. Several French officers and soldiers were wounded by the savages, and all did their best. The Canadians, on the other hand, more hardened to Indian ways, simply looked on at the wild scene. Most of the British were rescued and were taken safely to Fort Edward. The French fired cannon from Fort William Henry to guide fugitives back. Those not massacred at once, but made prisoners by the Indians in the woods, were in nearly all cases ransomed by Vaudreuil, who afterwards sent them to Halifax in a French ship.

Such was the 'massacre of Fort William Henry,' about which people took opposite views at the time, as they do still. It is quite clear that, in the first instance, Montcalm did almost everything that any man in his place could possibly do to protect his captives from the Indians. It is also clear that he did everything possible during and after the massacre, even to risking his life and the lives of his officers and men. He might, indeed, have turned out all his French regulars to guard the captive column from the first. But there were only 2,500 of these regulars, not many more than the British, who were armed, who ought to have poured out every drop of rum the night before, and who ought to have started only at the proper time and in proper order. There were faults on both sides, as there usually are. But, except for not having the whole of his regulars ready at the spot, which did not seem necessary the night before, Montcalm stands quite clear of all blame as a general. His efforts to stop the bloody work—and they were successful efforts involving danger to himself—clear him of all blame as a man.

The number of persons massacred has been given by some few British and American writers as amounting to 1,500. Most people know now that this is nonsense. All but about a hundred of the losses on the British side are accounted for otherwise, under the heading of those who were either killed in battle, or died of sickness, or were given up at Fort Edward, or were sent back by way of Halifax. It is simply impossible that more than a hundred were massacred.

Still, a massacre is a massacre; all sorts of evil are sure to come of it; and this one was no exception to the rule. It blackened unjustly the good name of Montcalm. It led to an intensely bitter hate of the British against the Canadians, many of whom were given no quarter afterwards. It caused the British to break the terms of surrender, which required the prisoners not to fight again for the next eighteen months. Most of all, the massacre hurt the Indians, guilty and innocent alike. Many of them took scalps from men who had smallpox; and so they carried this dread disease throughout the wilderness, where it killed fifty times as many of their own people as they had killed on the British side.