Thayendanegea Brant acted as a tireless negotiator for the Six Nations to control their land without Crown oversight or control. He used British fears of his dealings with the Americans and the French to extract concessions. His conflicts with British administrators in Canada regarding tribal land claims were exacerbated by his relations with the American leaders.
Brant was a war chief, and not a hereditary Mohawk sachem. His decisions could be and sometimes were overruled by the sachems and clan matrons. However, his natural ability, his early education, and the connections he was able to form made him one of the great leaders of his people and of his time.
Joseph Brant, painted in London by Gilbert Stuart in 1786
The situation of the Six Nations on the Grand River was better than that of the Iroquois who remained in New York. His lifelong mission was to help the Indian to survive the transition from one culture to another, transcending the political, social and economic challenges of one of the most volatile, dynamic periods of American history. He put his loyalty to the Six Nations before loyalty to the British. His life cannot be summed up in terms of success or failure, although he had known both. More than anything, Brant's life was marked by frustration and struggle.
https://en.wikipedia.org/wiki/Joseph_Brant
His attempt to create pan-tribal unity proved unsuccessful, though his efforts would be taken up a generation later by the Shawnee leader Tecumseh.