When both England and France began colonizing the eastern part of North America in the seventeenth century, it was inevitable that their centuries-old European rivalry would manifest itself in the western hemisphere as well. The French in Canada and the English along the east coast of North America remained isolated from each other for about a century, but in the early 1750s the English colonists pushing west confronted French forces moving south into the area just below the Great Lakes Ontario and Erie. At the junction of the Allegheny and Monongahela rivers English colonists from Virginia began claiming land by constructing a fort. Before it was completed it was captured and strengthened by French and Indian forces who named it Fort Duquesne. A Virginia militia attempt to retake the fort in 1754 (led by George Washington in his first command) failed in its mission.

After some 150 years of salutary neglect, the London government committed troops to the colonies in an attempt to beat back the French incursion. Major General Edward Braddock's defeat at the Monongahela River in the summer of 1755 was a major factor in touching off an international war between England and her allies versus France and her allies. This was called the French and Indian War in the En-glish colonies, the Seven Years War in Europe.

The English colonists had a long and hostile relationship with the native American population. The French on the other hand had developed close ties with Canadian tribes, primarily the Algonquin in the Ontario region and the Hurons farther west, by working with them in trade and assisting their Indian allies in warfare. The major rival to the Algonquin and Huron tribes, the Iroquois Confederacy, at times cooperated with the French but strove for the most part to remain neutral when it came to the white colonists killing each other. The Iroquois Confederacy consisted of six nations (Mohawk, Oneida, Onondaga, Cayuga, Seneca, and Tuscarora) which for almost two centuries had overcome mutual antagonism to cooperate in establishing a fearsome power base in the region of modern New York. As the Anglo-French conflict began, the French seemed to have the upper hand, so the Iroquois tended to lean toward them as they considered their own interests.

In upper New York lived an Irish colonist named William Johnson, who originally came to the area to oversee his uncle's land holdings. He became friendly with the Mohawk tribe and married Chief Joseph Brant's sister. When the war's tide began to turn in England's favor by 1758, Johnson was active in trying to convince the Mohawks and their Iroquois confederates to openly support the English cause. Fearing the potential of the French-supported Hurons rising in the west, the Iroquois came to the conclusion that the English were their best bet to maintain power among the region's tribes. In the spring of 1759 they began making overtures to English commanders which the Europeans were glad to accept.

The summer of 1759 appeared to be a pivotal season in the war. The French had lost Fort Duquesne the previous summer and were preparing to mount an expedition to recapture it. That would divert the English strategy of mounting their own invasion of Canada. Geoffrey Amherst, overseeing the English effort in the colonies, appointed Brigadier General John Prideaux to attack the French bastion Fort Niagara, the strongest and most European-style fortification in North America. Prideaux led 3,000 English and colonial soldiers to Fort Oswego on the southeastern shore of Lake Ontario. There he met William Johnson with 1,000 Iroquois. Prideaux left 1,000 of his men behind to strengthen Fort Oswego, while his remaining 2,000 soldiers and 1,000 Indians took to canoes along Lake Ontario's southern shore toward Fort Niagara.

Fort Niagara was under the command of Captain Pierre Pouchot, a talented engineer who had turned the fort into the formidable bastion that it was. He had a garrison of about 3,000 men earlier in the spring, but when he assumed the threat of English attack had passed he dispatched more than 2,500 of his men southward to join the operation against Fort Pitt (formerly Fort Duquesne). Pouchot had in his fort about 30 Seneca Indians, and had been using Seneca scouts for some time with satisfactory results. He had no idea that the Confederation had changed sides until Prideaux's men landed on 7 July and attacked a working party outside the fort. He immediately sent messengers south to retrieve his troops as the English began construction of their first siege lines on 10 July.

Located on a peninsula where the Niagara River joins Lake Ontario, the French fort had access to support by water, but it was the return of the troops he had dispatched earlier on which Pouchot depended. He was preparing for the siege when he called a truce in order for the leader of his Senecas to speak to their Iroquois brethren with the English. The Seneca in the fort had been unaware of any change in Confederation loyalties and argued in favor of remaining with the French. The Iroquois representatives pointed out the perceived power shift and the need to change sides. On 14 July, after three days of talks, the Seneca leader suggested both Indian forces withdraw southward to the island of La Belle Famille and let the Europeans fight among themselves. Johnson managed to keep his allies loyal, but Pouchot gave his Senecas free passage out of the fort rather than worry about their loyalty in the midst of the siege. Although the pro-English Iroquois did not retreat, neither did they take any further part in the battle, so the whites did indeed have to fight it out among themselves without the Iroquois shedding any confederate blood.

During the talks Pouchot did what he could to strengthen his defenses while the English continued to dig their trenches. On the 14th they opened fire from 250 yards away. Three days later English howitzers placed on the opposite side of the Niagara River began bombarding the fort as well. The fire was so intense that most of the French artillery was knocked out and few French soldiers would risk exposing themselves to engage in repairs. On the 18th Prideaux was killed by standing too close to a mortar as it fired, and Johnson assumed command. By 20 July the English were firing from a mere 80 yards away and the situation inside the fort looked bleak.

Then both French and English saw about 1,600 French reinforcements canoeing toward the fort from the south. The English dispatched some Iroquois to alert the Indians among the French to the situation, hoping to keep them out of the fighting. Johnson also sent 350 soldiers and 100 New York militia to cover the road approaching from the south. Some 500 Iroquois took up positions in the woods on either side of the road. When the French approached early in the day on the 24th, they had been abandoned by their Indian allies and numbered but 600 soldiers, marines, and Canadian militia. They rushed the English position but were blasted by seven volleys of English fire, then harried on their retreat by the hidden Iroquois.

Pouchot had seen the fighting through his telescope, but was unsure of the outcome until the English ceased firing and offered surrender terms: personal safety guaranteed, but imprisonment rather than parole. The French commander accepted on 25 July.

The English victory at Fort Niagara was a success in two ways. Capture of the fort gave them control of Lake Ontario, meaning no support for the key French strongholds of Montreal and Quebec would arrive from the west, nor would any French forces in the west receive any further aid from French shipping arriving up the St. Lawrence River, their only access into Canada. Second, by diverting the French attack on Fort Pitt, the Ohio Valley did not fall back into French control; the English could focus their effort on Quebec and Montreal without having to cover their rear. When Quebec fell in September 1759, the French and Indian War was as good as over, although the Seven Years War continued in Europe and India until 1763.

Thus, Fort Niagara proved a key acquisition for the English and their colonial ambitions. Unfortunately, it proved fatal to the Iroquois. Siding with the winners did not help them as they had hoped. They had viewed their aid to the English as temporary, "only one of many pragmatic policy shifts in the long history of relations between the Confederacy and the British Crown. But this time the tilt toward the British would prove irrevocable, and its consequences would exceed any that the Iroquois could have intended. For the commitment to an active alliance, in fact if not in name, meant the acceptance of dependency" (Anderson, The Crucible of War, p. 333). Once established on the frontier, British power served the colonists, not the Iroquois. When war broke out between the English and their colonies in 1775, again the Indians played a primarily passive role, engaging in active warfare primarily in the trans-Appalachia lands, away from the main theater of war. The Iroquois aided the English military at times, but the colonial victory meant an end to major power assistance and ultimate defeat at the hands of the expansionist United States.