[6]: 210 Guyasuta first appears in colonial records when he met the 21-year-old George Washington, who had been assigned to deliver a message to the French commandant at Fort Leboeuf.

In late 1753, Virginia Governor Dinwiddie appointed newly-commissioned Major Washington as a special envoy to demand that the French vacate the Ohio Country, which the British had claimed.

[7] Arriving with Christopher Gist in Logstown on November 23, Washington held council with Native American leaders, including Shingas, Scarouady, and Tanacharison.

Tanacharison tried to return the wampum to Saint-Pierre, "who evaded taking it, & made many fair Promises of Love & Friendship; said he wanted to live in Peace & trade amicably with them; as a Proof of which, he wou’d send some Goods immediately down to the Logstown for them.

[14][15]: 158 Guyasuta was recognized for his participation in the victory, and in late 1755 was selected to lead a party of twenty Senecas to visit Montreal accompanied by Philippe-Thomas Chabert de Joncaire, who served as interpreter.

[6]: 210 In August 1756, Guyasuta participated in the capture of Fort Granville, taking captive 22 soldiers, 3 women, and 5 or 6 children, among whom were 15-year-old Simon Girty, his three brothers, and his mother and stepfather.

Simon Girty was adopted by Guyasuta and lived with him until 1764, when by arrangement with Colonel Henry Bouquet, over 200 white captives were handed over to British authorities.

On November 14 1764, Guyasuta took Girty to Bouquet's camp on the Muskingum River and handed him over directly to Lieutenant Alexander McKee, assistant deputy agent for the British Indian Department.

Having learned nine Native American languages during his years with the Seneca, Girty became an interpreter for the British Army and, in this role, encountered Guyasuta frequently during negotiations.

James Smith described the battle: Guyasuta's warriors decapitated the bodies of Grant's highlanders and impaled the heads on stakes in front of the fort.

[11]: 373–74 In July 1759, Guyasuta, two other chiefs and sixteen warriors of the Six Nations, along with a number of Lenape, Shawnee and Wyandot leaders, attended a conference at Pittsburgh with George Croghan, William Trent, Colonel Hugh Mercer, and the officers of Fort Pitt.

[22]: 182  Croghan learned that Guyasuta and Tahaiadoris were planning to incite the tribes around Detroit, the Ottawa, Potawatomi, and Wyandot, to surprise the garrison there and take over the fort, giving their warriors access to abundant stores of guns and ammunition.

[24] Guyasuta's interpreter revealed the plot to the commander at Fort Detroit, and an Odawa chief confirmed the allegation, identifying Guysuta as the "bad bird among us."

Even Jeffery Amherst, Commander-in-Chief of the Forces in the British Army, dismissed the scheme, doubting that the tribes could coordinate such a massive and complex operation.

[2] When Colonel Henry Bouquet arrived with a relief column, Guyasuta joined Delaware and Shawnee warriors in trying to prevent it from reaching the fort.

[11]: 377–78 [Note 2] Guyasuta signed a preliminary peace agreement on August 12 1764, and participated in the handover of captives,[2] including his own adopted son, Simon Girty.

[16] On May 10 1765, Guyasuta attended a peace conference at Fort Pitt to discuss the resumption of trade relations between Pennsylvania and the Western Indians after Pontiac's War.

He made a speech which summarizes the distrust and frustration most Native Americans felt after inconsistent treatment by the British government: In 1770, Washington was traveling along the Muskingum River looking for lands suitable to be given to Virginia veterans in payment for their services.

McClure was on his way to preach to the Lenape people, and later described the encounter in his diary: On November 11, the Pennsylvania Gazette reported: At the outset of the American Revolutionary War, Guyasuta sided with the British, like most Iroquois, although he initially argued that the Seneca should remain neutral.

[5]: 129–133  At a conference at Fort Pitt in October 1775, Guyasuta offered to help implement the terms of surrender agreed to by the Shawnee at the end of Lord Dunmore's War.

[2] Another conference at Fort Pitt was called in July 1776 to enable Guyasuta, as the representative of the Six Nations in the Ohio and Allegheny valleys, to define his position in the conflict between England and the American colonies.

"[11]: 403  Together with General Richard Butler,[35] Guyasuta worked to persuade the Mingo to remain neutral,[36]: 109–16  and in recognition of his services, the Continental Congress awarded him a silver gorget and a colonel's commission.

"[13] Within a year, however, Guyasuta's stance had changed, and he accompanied his nephew Cornplanter to the Siege of Fort Stanwix, where he took part in the Battle of Oriskany in August 1777.

In December 1777, his former adopted son Simon Girty reported that he had killed settlers near Fort Ligonier, as described in a letter from Colonel John Gibson to George Washington: "Simon Girty, a Messenger dispatched by General Hand to the Seneca towns on the Heads of the Allegeney, Returned here a few days agoe, he informs us Guashota a Chief of them had Returned from War, that he had killed four people near Legonier.

"[37] In August and September 1779, Lieutenant Colonel Daniel Brodhead directed a series of raids against the Senecas living in southwestern New York State.

[2][11]: 403 On July 13 1782, in one of the final actions of the American Revolution, the settlement of Hannastown, Pennsylvania was attacked and destroyed by a British military detachment of sixty Canadian rangers from Fort Niagara and a hundred Seneca warriors led by Guyasuta.

[2] After the American Revolutionary War, the aging Guyasuta worked to establish peaceful relations with the new United States, as his nephew Cornplanter became an influential diplomatic figure.

"[4]: 99 [47]: 443  According to one account, after Guyasuta had not been seen for several days, O’Hara found him dead on his cabin floor in 1794,[14] and he was buried nearby with his rifle, tomahawk, knife, trinkets, and trophies in his coffin.

[60] A brass plaque at the base of the statue states that Guyasuta "was probably buried in the area now occupied by the north end of the Highland Park Bridge.