The decision could have significant implications for how resource revenue, such as from mining and forestry, are shared with the country’s Indigenous communities and for the role of courts in reconciliation between First Nations and Canadian governments.

The negotiated settlement is expected to be sizable. During the case, Canada argued that the beneficiaries were owed at most about 1.8 billion Canadian dollars, or about $1.3 billion. But Nobel Prize-winning economist Joseph Stiglitz — who was called by the First Nations groups to testify — told the court that his economic model showed the figure was upward of $90 billion.

In its decision, the court rebuked Canada’s “longstanding and egregious” breach of the treaties — entered into in 1850, more than a decade before Canada confederated — between the Crown and the Anishinaabe of Lake Huron and Lake Superior in what is now Northern Ontario. The Crown was represented by Ontario’s attorney general in the case, and Canada’s attorney general was also a respondent in the claim.

“For well over a century, the Crown has shown itself to be a patently unreliable and untrustworthy treaty partner,” Justice Mahmud Jamal wrote. “… It has lost the moral authority to simply say ‘trust us.’”

At the time, the Anishinaabe and the Crown agreed that the Anishinaabe would cede their territories in exchange for, among other things, an annual payment. A novel clause in that agreement said that if the land produced an amount in the future that would allow the government to increase the annuity “without incurring loss” then it “shall” be increased “from time to time.”

Jamal called for a “declaration setting out the rights and obligations of the treaty parties, including the Crown’s obligations under the Augmentation Clause,” in addition to the negotiated settlement. If a settlement cannot be reached between the parties, he said, the Crown must “exercise its discretion” to determine an appropriate amount of compensation.

The federal government had agreed that some compensation was owed, but Ontario argued it has no legal obligation in part because it has incurred billions in losses from building infrastructure needed for development.

The two agreements, commonly called the Robinson Treaties, were not followed, the descendants of the First Nations people who signed it successfully argued.

“Billions of dollars have since been generated from the Treaty territories from forestry, mining, and other resource development,” First Peoples Law, which was involved in the case, said in a statement last year.

“At the same time, the Anishinaabe Treaty beneficiaries continue to receive the same annual payment of $4 per person that they received in 1875.”

The court found that paying the treaty beneficiaries a “shocking” $4 each per year without an increase since 1875 “can only be described as a mockery” of the document’s intended promise.

It also commented on how historical treaties should be interpreted, emphasizing that courts “must consider both the words of a treaty and the historical and cultural context” and take into account how the agreement would have been understood by each party at the time. The Canadian government recognizes 70 historical treaties between the Crown and 364 First Nations signed between 1701 and 1923.

Harley Schachter, counsel for Red Rock First Nation and Whitesand First Nation, celebrated the ruling in a news release, saying: “The Supreme Court has ruled today that governments are not above the law,” he said. “It is a sacred relationship between First Nations and the Crown. It is a partnership, not a dictatorship.”

The Robinson Huron Treaty Litigation Fund, which represents another group of Huron claimants who reached a 10 billion Canadian dollar settlement with the federal and provincial governments last year, said it was “very happy with the decision.” The ruling vindicated its position, it added, including that “the Treaty contains a sacred promise to share the wealth of the territory in accordance with the Anishinaabe legal principles of reciprocity, respect, responsibility and renewal.”

Amanda Coletta contributed to this report.