[9] Many of the Haudenosaunee people allied with the British during the American Revolutionary War, particularly warriors from the Mohawk, Cayuga, Onondaga and Seneca nations.

The Crown worked to resettle native Loyalists in Canada and provide some compensation for lands lost in the new United States.

The new lands granted to Six Nations reserves were all near important Canadian military targets and placed along the border to prevent any American invasion.

After the war, Mohawk leaders John Deseronto and Joseph Brant met with British commander Sir Frederick Haldimand to discuss the loss of their lands in New York.

The group of Mohawk originally led by John Deseronto, who died in the town named after him, settled on the Bay of Quinte known as Tyendinaga.

[14] Joseph Brant led a large group of Iroquois to settle in what is now referred to as "Six Nations of the Grand River."

A 1785 census recorded 1,843 Natives living on the Grand River reserve, including 548 Mohawk, 281 Cayuga, 145 Onondaga, 262 Oneida, 109 Tuscarora, and 98 Seneca.

As the government did for European Americans, the Indian department provided the Haudenosaunee with some tools and other provisions for resettlement, including such items as saws, axes, grindstones, and chisels.

In 1785, the government built the first Protestant church in Upper Canada (now Ontario) on the reserve; it was known as Her Majesty's Royal Chapel of the Mohawks.

In 1797, Brant founded one of the earliest Masonic Lodges in Upper Canada; he achieved the rank of its Worshipful Master.

In 1795, the Grand River chiefs empowered Joseph Brant to sell large blocks of land in the northern section, which the Haudenosaunee were not using at the time.

At this time, the population on the reserve was declining; some Haudenosaunee left the Grand River for traditional native communities in New York.

By 1800, two-thirds of the Haudenosaunee had not yet adapted to the style of subsistence agriculture maintained by separate households that the Canadian government encouraged.

In 1813, the chiefs and councillors of the Six Nations residing in the state of New York would declare war on the provinces of Upper and Lower Canada.

The Six Nations people were originally given 10 km (6 miles) on either side of the entire length of the Grand River, although much of the land was later sold.

In the late 19th century, the Scottish doctor Joseph Bell excavated skulls of indigenous people in the six nations.

In 2020, the journalists David Bruser and Markus Grill, supported by the ethnologist Nils Seethaler, succeeded in finding the skulls in the anatomical collection of the Berlin Society for Anthropology, Ethnology and Prehistory.

The population consists of the following bands:[22] The Six Nations of the Grand River Elected Council is a governing body established to run the affairs of the reserve in 1924, formed under the Indian Act.

Members of the Six Nations attended the Mohawk Institute, a residential school which was the subject of numerous abuse allegations.