The French and Indian War, known in Europe as the Seven Years War, begins in earnest in 1756.

At the start of the war, no French regular army troops are stationed in North America, and few British troops.

New France is defended by about three thousand troupes de la marine, companies of colonial regulars (some of whom have significant woodland combat experience).

The colonial government recruits militia support when needed.

Most British colonies muster local militia companies, generally ill trained and available only for short periods, to deal with native threats, but do not have any standing forces.

Virginia, because of its large frontier, has several companies of British regulars.

The colonial governments are used to operating independently of each other and of the government in London, a situation that complicates negotiations with native tribes.

Their territories often encompass land claimed by multiple colonies.

After the war begins, the leaders of the British Army establishment tried to impose constraints and demands on the colonial administrations.

The governments of both Britain and France, following the beginning of open conflict between French and British colonists in 1754 with the Battle of Jumonville Glen, had sent regular army troops to North America to further contest the disputed territories of the Ohio Country and other border areas, including the frontier between the French province of Canada and the British province of New York, an area in present-day Upstate New York that is largely controlled by the Iroquois nations.

Part of the British plans for 1755 had included an expedition to take Fort Niagara at the western end of Lake Ontario.

The planned route for this expedition had followed the Oswego River to the lake, with a major base of operations at the mouth of the river (where the present-day city of Oswego, New York is located).

Under the direction of William Shirley, the governor of the Province of Massachusetts Bay, the original Fort Oswego had been reinforced, and two additional forts, Fort George and Fort Ontario, had been built in 1755.

The planned expedition to Fort Niagara never took place due to logistical difficulties, and the fortifications around Oswego had been manned during the winter of 1755–56.

The French in 1755 had the only large naval vessels on Lake Ontario, and moved freely about the lake, between Fort Niagara in the west and Fort Frontenac at the head of the Saint Lawrence River.

Following the failure of aggressive British campaign plans in 1755, a chain of forts along the Mohawk River riverway connecting the Hudson River to Lake Ontario have been garrisoned during the winter of 1755–1756.

The largest garrison is left at Fort Oswego, at the end of the chain, which depends on the others for its supplies.

Two forts along the Oneida Carry are a key element of this supply chain.

The Oneida Carry traverses an unnavigable section between present Rome, New York and Wood Creek that is between one and six miles long, depending on seasonal water levels.

Fort Williams, on the Mohawk, is the larger of the two, while Fort Bull, several miles north of Fort Williams on Wood Creek, is little more than a palisade surrounding storehouses.

Fort Bull is garrisoned by a small number of men from Shirley's Regiment under William Bull, and holds large quantities of military stores, including gunpowder and ammunition, destined for use in the 1756 campaign.

French military leaders in Canada decide in early 1756 to send a raiding expedition to attack Oswego's supply line. 

A company of men had left Fort de La Présentation on March 12 to begin an overland trek toward the Oneida Carry.

Under the command of Lieutenant Gaspard-Joseph Chaussegros de Léry, a Canadian-born seigneur, the force consists of eighty-four troupes de la Marine, one hundred and eleven Canadian militiamen, and one hundred and ten natives, mostly Iroquois but also some Hurons.

Chaussegros de Lery, having joined the colonial army in 1733 and become an assistant engineer in 1739, had taken part in raids against the British in New England, helped maintain French fortifications in New France and was in charge of the construction of Fort Saint-Jean.

In 1753, he married Louise, the daughter of François Martel de Brouague, commandant of the Coast of Labrador.

Léry's war party, after nearly two weeks of difficult winter travel, arrives on March 24 near the carry.

Léry's men capture twelve British men near Fort Bull early on March 27, while others escape capture and run toward Fort Williams.

Learning from the prisoners of Bull's minimal defenses, he decides to attack immediately.

As he has no field pieces, the only possibility is to attempt storming the fort by surprise.

The fort's defenders manage to close its gates just before the French force arrives.

The attackers managed to fire through loopholes in the fort's walls to distract the garrison, which responds by throwing rocks and grenades over the walls.

After Bull refuses several calls to surrender, the gate is taken down by the use of axes, and the attackers storm into the fort.

Nearly all of the small garrison is killed and scalped, according to a report by Sir William Johnson, who inspected the carnage when he eventually arrived at the head of a relief column.

Léry's men set fire to the works, which include forty-five thousand pounds of gunpowder.

The resulting conflagration destroys the wooden fort.

Léry will be promoted to captain for his successful command.

The loss of the supplies at Fort Bull effectively ruins any British plans for military campaigns against French forts on Lake Ontario, including Shirley's plan to attempt the expedition against Fort Niagara, and may be a contributing factor to the French capture of Fort Oswego in August 1756.

Masschusetts governor William Shirley had assumed command of British forces in North America following the death of Major General Edward Braddock in the disastrous expedition to take Fort Duquesne.

Shirley had laid out his plans for 1756 at a meeting in Albany in December 1755.

In addition to renewing the efforts to capture Niagara, Crown Point and Duquesne, he had proposed attacks on Fort Frontenac on the north shore of Lake Ontario and an expedition through the wilderness of the Maine district and down the Chaudière River to attack the city of Quebec.

Bogged down by disagreements and disputes with others, including William Johnson and New York's Governor Sir Charles Hardy, Shirley's plan had little support.

The Duke of Newcastle, Prime Minister of Great Britain, had replaced him in January 1756 with Lord Loudoun, with Major General James Abercrombie as his second in command.

Neither of these men have as much campaign experience as the trio of officers France sent to North America.

French regular army reinforcements arrive in New France in May 1756, led by Major General Louis-Joseph de Montcalm and seconded by the Chevalier de Lévis and Colonel François-Charles de Bourlamaque, all experienced veterans from the War of the Austrian Succession.

England formally declares war on France on May 18, 1756, nearly two years after fighting had broken out in the Ohio Country.

This expands the war into Europe, later to be known as the Seven Years' War.

French and native raiding parties under the command of Louis Coulon de Villiers, following orders of the Governor of New France, had begun in May 1756 to harass the Oswego garrison from a camp on Henderson Bay (south of present-day Sackett's Harbor, New York).

Montcalm had arrived in Montreal in May 1756 to lead the French army troops.

He and Governor Vaudreuil had taken an immediate dislike to one another, and disagreed over issues of command.

Concerned over the massing of British troops at the southern end of Lake George, Montcalm had first gone to Fort Carillon on Lake Champlain to see to its defenses.

Vaudreuil had meanwhile begun massing troops at Fort Frontenac for a potential assault on Oswego.

Following favorable reports from the raiding parties, Montcalm and Vaudreuil had decided to make the attempt. 

Montcalm had left Carillon on July 16 under the command of the Chevalier de Levis, reaching Montreal three days later.

He left two days later for Fort Frontenac, where French troops were gathering along with a large company of natives.

French forces include the battalions of La Sarre, Guyenne, and Béarn, troupes de la marine, and colonial militia, while natives, numbering about two hundred and fifty, have come from all over the territories of New France.

The total size of the force is reckoned to be three thousand men.

Governor Shirley had received word in March 1756 that he was to be replaced by John Campbell, 4th Earl of Loudoun.

Loudoun's second in command, General James Abercrombie, had only arrived in Albany in late June, and Shirley had spent the intervening time shoring up the supply line to Oswego in anticipation of leading an expedition against the French forts on Lake Ontario.

William Johnson had traveled in June to the Iroquois headquarters at Onondaga, successfully negotiating support for the British side with the Iroquois, Shawnee, and Delaware, forces that Shirley also hopes to use for his expedition.

Shirley had also hired two thousand armed "battoemen", men experienced in sailing and shipbuilding.

Under the command of John Bradstreet, who had been appointed appointed as Governor Shirley's adjutant general in 1755, these men successfully resupply the forts at Oswego in July, although they are attacked by a French raiding party on their way back, suffering sixty to seventy casualties.

Captain Bradstreet survives but his warnings to Governor Shirley and Lord Loudon of the weak condition of Fort Oswego are largely ignored amid their ongoing power struggle.

When Loudoun arrives in Albany in late July, he immediately cancels Shirley's plans for an Oswego-based expedition.

François-Pierre de Rigaud, the governor's brother, had led an advance force of seven hundred to meet with Villiers' force at Sackett Harbor before the main force set out on August 4.

Crossing at night to what is now called Wolfe Island, the vanguard of the main body spent the day there before crossing at night to Sackett's Harbor.

The entire force had assembled there by August 8, and set out the next day for Oswego.

Troops under Rigaud and Villiers had marched overland toward Oswego on August 9, while Montcalm and the remaining force moved close to the shore in bateaux, landing about two miles (three point two kilometers) east of Fort Ontario early on August 10.

Their stealth in movement has been successful, and the British do not discover them until a small patrol boat spots them the next morning.

Larger boats sent by the British are driven away by the French field artillery.

Montcalm's engineer goes to survey the British defenses, accompanied by other officers and a party of natives.

One of the natives, eager for a scalp, mistakes the engineer for a British soldier at one point and shoots him dead.

Montcalm asks Pierre Pouchot to continue with the work of determining how to besiege the British positions.

The French had opened siege trenches and begun working toward Fort Ontario on the night of August 11–12.

The fort's defenders exchange cannon and gunfire with the French colonists and natives until late in the day on August 13, at which point, under orders from Mercer, they abandon the fort even before the siege trenches have reached their goal.

Immediately capitalizing on this, Montcalm occupies the fort and begins the construction of batteries on the western edge of the height, where they can reach Fort Oswego's exposed east side.

Moving with all speed, the French have nine working cannon established by the morning of August 14.

When these open fire on the exposed stonework of Fort Oswego, the walls crumble under the onslaught.

The garrison, whose cannon are all pointed away from the river (not expecting enemy fire to come from this direction), eventually turn their guns around, and the French fire is returned to some effect.

However, Montcalm had ordered Rigaud to lead some men across the river upstream from the fortifications, and these men, who make an unopposed crossing under somewhat difficult conditions, appear on the edge of the clearing outside Fort Oswego about the same time that Colonel Mercer is struck and killed by a French shell.

After a short council Lieutenant Colonel John Littlehales, who has taken over command from Mercer, raises the white flag.

The British surrender about seventeen hundred people, including laborers, shipbuilders, women and children.

Montcalm refuses to grant the defeated army the honors of war, as he feels that Littlehales had failed to earn them by putting up more of a fight.

When the fort is opened to the Canadian militia and natives, they rush in and begin plundering the fort, opening the barrels of rum and getting drunk on the contents.

Some of the British try to escape amid the confusion, and are tomahawked and killed by drunken French or natives.

In the aftermath, Montcalm and the natives under his command disagree about the disposition of prisoners' personal effects.

The Europeans do not consider them prizes and prevent the natives from stripping the prisoners of their valuables, which angers the natives.

Colonel Littlehales is seized by a group of Abenakis and badly beaten for his cowardice and bad behavior.

General Montcalm, shocked by the behavior, is eventually able to prevent further killings by a promise of presents.

He next orders the destruction of all the supplies the French do not take, as well as the boats under construction, after which the entire company, including the prisoners, travels to Montreal.

Loudoun had finally dispatched reinforcements from the 44th Regiment of Foot and Bradstreet's battoemen toward Oswego on August 12.

When these troops reached the Oneida Carry they learned that Oswego had fallen; after destroying the fortifications there, they retreat to German Flatts, where Loudoun orders them to stay to prevent further French advances.

Loudoun will spend significant effort over the following months to pin the blame for the loss on William Shirley.

He will be cleared of all formal charges in an inquiry, but with numerous irregularities highlighted.

Shirley's political connections in London will enable him to acquire other desirable posts later in his career.

Oswego will be effectively abandoned until 1758, when the British reoccupy the area, and Bradstreet will lead an expedition that captures and destroys Fort Frontenac.

It will be used again in 1759 as a departure point for a successful expedition against Fort Niagara, and in 1760 by Jeffrey Amherst's army as it moves toward Montreal.

Louis-Antoine, Comte de Bougainville, questioning some of the men captured during the Battle on Snowshoes, learns from them the disposition of men and materials all the way from Albany to Fort William Henry.

Other captured British end up as slaves to the natives.

Thomas Brown, who will publish a pamphlet that vividly describes his captivity, will spend almost two years in slavery, traveling as far as the Mississippi River before reaching Albany in November 1758.

Bougainville was born in Paris, the son of a notary, on either November 11 or 12, 1729. 

In early life, he had studied law, but soon abandoned the profession. 

In 1753 he had entered the army in the corps of musketeers.

At the age of twenty-five he had published a treatise on integral calculus, as a supplement to De l'Hôpital's treatise, Des infiniment petits.

He had been sent in 1755 to London as secretary to the French embassy, where he was made a member of the Royal Society.

Stationed in Canada in 1756 as captain of dragoons and aide-de-camp to the Marquis de Montcalm, 
Bougainville had taken an active part in the capture of Fort Oswego in 1756.

Fort William Henry, built in the fall of 1755, is a roughly square fortification with bastions on the corners, in a design that is intended to repel native attacks but is not necessarily sufficient to withstand attack from an enemy that has artillery.

Its walls are thirty feet (nine point one meters) thick, with log facings surrounding an earthen filling.

Inside the fort are wooden barracks two stories high, built around the parade ground.

Its magazine is in the northeast bastion, and its hospital is located in the southeast bastion.

The fort is surrounded on three sides by a dry moat, with the fourth side sloping down to the lake.

The only access to the fort is by a bridge across the moat.

The fort is capable of housing only four to five hundred men; additional troops are quartered in an entrenched camp seven hundred and fifty yards (six hundred and ninety meters) southeast of the fort, near the site of the 1755 Battle of Lake George.

Fort William Henry had been garrisoned during the winter of 1756–57 by several hundred men from the 44th Foot under Major Will Eyre.

In March 1757 the French send an army of fifteen hundred to attack the fort under the command of the governor's brother, François-Pierre de Rigaud.

Composed primarily of colonial troupes de la marine, militia, and natives, and without heavy weapons, they besiege the fort for four days.

Lacking sufficient logistical and artillery support, and hampered further by a blinding snowstorm on 21 March, French forces are unable to take the fort and the siege is called off.

Although the French fail to take the fort itself, their forces do destroy three hundred bateaux and several lightly armed vessels beached on the shore, a saw-mill and numerous outbuildings before retreating.

Loudoun's plan for the 1757 campaign is focused on a single expedition aimed at the heart of New France, the city of Quebec.

Submitted to the government in London in September 1756, the plan calls for a purely defensive posture along the frontier with New France, including the contested corridor of the Hudson River and Lake Champlain between Albany, New York and Montreal.

Following the Battle of Lake George in 1755, the French had begun construction of Fort Carillon (now known as Fort Ticonderoga) near the southern end of Lake Champlain, while the British had built Fort William Henry at the southern end of Lake George, and Fort Edward on the Hudson River, about sixteen miles (twenty-six kilometers) south of Fort William Henry.

The area between William Henry and Carillon is a wilderness dominated by Lake George.

Loudoun's plan depends on the expedition's timely arrival at Quebec, so that French troops will not have the opportunity to move against targets on the frontier, and will instead be needed to defend the heartland of the province of Canada along the Saint Lawrence River.

However, political turmoil in London over the progress of the Seven Years' War both in North America and in Europe has resulted in a change of power, with William Pitt the Elder rising to take control over military matters.

Loudoun consequently does not receive any feedback from London on his proposed campaign until March 1757.

Before this feedback arrived he had developed plans for the expedition to Quebec, and had worked with the provincial governors of the Thirteen Colonies to develop plans for a coordinated defense of the frontier, including the allotment of militia quotas to each province.

When William Pitt's instructions finally reach Loudoun in March 1757, they call for the expedition to first target Louisbourg on the Atlantic coast of Île Royale, now known as Cape Breton Island.

Although this does not materially affect the planning of the expedition, it is to have significant consequences on the frontier.

The French forces on the Saint Lawrence will be too far from Louisbourg to support it, and will consequently be free to act elsewhere.

Loudoun assigns his best troops to the Louisbourg expedition, and places Brigadier General Daniel Webb in command of the New York frontier.

He is given about two thousand regulars, primarily from the 35th and 60th (Royal American) Regiments.

The provinces are to supply Webb with about five thousand militia.