Billy Diamond was the first Grand Chief of the Grand Council of the Crees. When he signed the James Bay Agreement in 1 975 he was both Chief of Waskaganish and Grand Chief. While he was not the Chief Negotiator of the Cree team when the James Bay and Northern Quebec Agreement u as signed, he was the Grand Chief and as such had a large influence on many of the decisions that were made. As the main spokesperson for the Creed he refused to allow the American Indian Movement to influence the decisions made by the Crews. Similarly, when the Indians of Quebec Association wanted to set up negotiations with the governments on behalf of all Aboriginal Peoples in Quebec, Billy expressed his view that the Crews should negotiate their own settlement. His argument to the IQA was that his people needed a large measure of control over the education, health services, housing, economic development, environmental and social protection, local and regional government and the management of important issues in the Cree traditional territory. He said that the issue was not money, but the future of the Crees.
After the Agreement was signed Billy remained as Grand Chief, and he also was appointed as Chairman of the Cree School Board. As Chairman of the School Board he fought for funding to completely replace the worn and inadequate buildings left to the Board by the Department of Indian and Northern Affairs. From the time he was appointed until 1987 when he resigned, he managed to accomplish this task.
Once the James Bay and Northern Quebec Agreement was signed, the governments of Canada and Quebec were slow to implement what they had promised in 1975. This culminated in a gastroenteritis epidemic in the Cree communities where many people were sick and some died: at the same time Quebec moved in with an attempt to seize the Cree Health Board. The Grand Council, with Billy at its head, replied with a court case against Quebec and Canada which eventually led to out-of-cort settlement and a more adequate funding regime for the Board. Billy then launched a lobby campaign in Ottawa with the aid of Gary George and Robert Epstein. In 1982 Canada replied by providing for the construction of sewer and water systems in the Cree communities, renovation of the Health Clinics in the communities, building airports in Waskaganish, Eastmain and Wemindji; and some increased funding for housing for housing. This resulted in a negotiation with Canada on self-government that in 1984 brought about the passage of the Cree Naskapi of Quebec Act.
The Cree Naskapi Act was the first time in Canada that Aboriginal communities were created as corporations and were not under the Indian Act. As a result the Crees have been able to make their communities prosper and become modem communities with the services that thee require. When teh Act was being written it became known that Canada did not have the intention to provide the funding necessary for its implementation. When Billiy got wind of this, he called the minister of Indian and Northern Affairs to assure him that he, himself would stand up in Parliament and tell the members of the House not to pass the Bill if Canada did not negotiate a funding package to implement it. The negociation on this, led by Norman Hawkins, based the funding of the Cree communities on the funding if federal municipalities in the Northwest Territories. This fact brought a new dynamic into Aboriginal –Canadian relations. If non-native communities in the NWT had high standards for the services they provided, why didn't these same high standards also apply to other Aboriginal communities, as they now did to the Cree? Canada has been slow to apply such up-to-date standards to other communities but some have succeeded. Few realize that Billy led the way to raising the standards.
In his attempt to bring public attention to the Cree cause, Billy, along with other Cree leaders, went to visit the Pope, which caught the attention of newspapers across Canada. Just visiting the Pope brought Crees into the attention of the Quebec public. "What is this Cree Chief doing in the Vatican," they probably thought. As it happened the very day he was there, it came to light that the Premier Rene Levesque announced that he would be going to see the Pope. The political cartoon in the next day's La Presse was a picture of the Pope greeting Premier Lévesque saying: "You're from Quebec, eh? Do you know Billy Diamond?" While the Vatican visit by Billy was the start of the now thirty-year engagement of the Crees in International Affairs, the Cree problems with getting on with the Quebec Government would await another day.
In 1982 Billy set up Air Creebec. This initiative was bitterly fought by the Government of Quebec, that did not want to see Austin Airways from Ontario taking over air transport in Northern Quebec by holding a controlling interest in Air Creebec. As a result, the Crees negotiated to hold the controlling interest themselves and in later years bought out Austin's 49% interest. Quebec fought the Cree proposal by organizing a consortium of local airlines in Northern Quebec, called Propair, to compete against the Crees. At the time, to start an airline you had to hold the licenses to the air routes that you wanted. Billy lobbied politicians in Ottawa and was eventually granted these licences when some senior federal politicians supported the Cree proposal. Billy was the first president of Air Creebec and it grew under his leadership and, later, under the leadership of his brother Albert.
In 1984 Billy decided not to run for the office of Grand Chief. He went home to Waskaganish and sometime later became Chief once again in his home community. At home, he decided that the community needed economic development and so another chapter in his life opened. His efforts there led to the opening of a boat factory in a joint venture with Yamaha; the building of Kanio Kashee Lodge; the opening of a mini mall; training of community members to work in tourism; and the purchase by the community of Moosonee Transport, a company that barges goods around to isolated communities on James Bay.
The Cree fight against the Great Whale and NBR Hydroelectric Projects, and later in defence of their rights in the contexts of the Quebec referendum on separation, had created the situation. Billy was called upon by then Grand Chief Ted Moses to begin the healing process between the two peoples. Billy brought delegations of Crews to Quebec and delegations of Quebec officials to the communities. He returned to his community having put relations on a good course for both parties. This process of reconciliation eventually led to the negotiation of the Paix des Braves of which Billy negotiated the chapters concerning future development: the Eastmain 1 AND Eastmain 1A Projects.
During the building of these projects Billy helped in the formation of a Cree consortium of local construction companies, and other types of companies and he brought about many joint ventures and partnerships with local non-native companies and some from Montreal.
Also during the construction of these projects Billy was the president of Nikamowin Corporation, a remedial works company.
In 1987 he was honoured with the Order of Quebec.
Billy received an honourary doctorate from Ottawa's Carelton University, in 1998