ST-ANNE-DE-BEAUPRE, Quebec >> Pope Francis celebrated Mass on Thursday at Canada’s national shrine and came face-to-face with a long-standing demand from Indigenous peoples: to rescind the papal decrees underpinning the so-called “Doctrine of Discovery” and repudiate the theories that legitimized the colonial-era seizure of Native lands and form the basis of some property law today.

Right before Mass began, two Indigenous women unfurled a banner at the altar of the National Shrine of Sainte-Anne-de-Beaupre that read: “Rescind the Doctrine” in bright red and black letters. The protesters were escorted away and the Mass proceeded without incident, though the women later marched the banner out of the basilica and draped it on the railing.

The brief protest underscored one of the issues facing the Holy See following Francis’ historic apology for the Catholic Church’s involvement in Canada’s notorious residential schools, where generations of Indigenous peoples were forcibly removed from their families and cultures to assimilate them into Christian, Canadian society. Francis has spent the week in Canada seeking to atone for the legacy and on Thursday added in another request for forgiveness from victims for the “evil” of clergy sexual abuse.

Beyond the apology, Indigenous peoples have called on Francis to formally rescind the 15th century papal bulls, or decrees, that provided the Portuguese and Spanish kingdoms the religious backing to expand their territories in Africa and the Americas for the sake of spreading Christianity. Those decrees underpin the Doctrine of Discovery, a legal concept coined in a 1823 U.S. Supreme Court decision that has come to be understood as meaning that ownership and sovereignty over land passed to Europeans because they “discovered” it. It was cited as recently as a 2005 Supreme Court decision involving the Oneida Indian Nation.

“These colonizing nation states, in particular Canada and the United States, have utilized this doctrine as the basis for their title to land, which ultimately really means the dispossession of land of Indigenous peoples,” said Michelle Schenandoah, a member of the Oneida Nation Wolf Clan. She was in Quebec City with a delegation from the Haudenosaunee Confederacy to raise the issue with church leaders.

“It’s been a long genocide over 500 years, and it still is valid law to this day,” she said.

Prime Minister Justin Trudeau cited the need for the Holy See to “address the Doctrine of Discovery,” as well as other issues including the return of Indigenous artifacts in the Vatican Museums, in his private talks with Francis on Wednesday, Trudeau’s office said.

Several Christian denominations in recent years have formally repudiated the doctrine. The Canadian bishops did so in 2016 and the umbrella organization of U.S. female Catholic religious orders, the Leadership Conference of Women Religious, formally asked Francis to do so in 2014 saying he should repudiate “the period of Christian history that used religion to justify political and personal violence against Indigenous nations and peoples and their cultural, religious, and territorial identities.”

Murray Sinclair, the First Nations chairman of Canada’s Truth and Reconciliation Commission, cited the doctrine in a statement this week welcoming Francis’ apology but calling on him to take responsibility for the full role of the church in the Canadian residential school system.

“Driven by the Doctrine of Discovery and other church beliefs and doctrines, Catholic leaders not only enabled the government of Canada, but pushed it even further in its work to commit cultural genocide of Indigenous peoples,” Sinclair said.

Church officials have insisted those papal decrees have long since been rescinded or superseded by other ones fully recognizing the rights of Indigenous peoples to live on their lands, and say the original bulls have no legal or moral bearing today. During the trip, Francis has reasserted repeatedly those rights and rejected the policies of assimilation that drove the residential school system.

But both the Vatican and Canadian trip organizers have confirmed that a new church statement is being prepared to address demands for a current, formal repudiation, though it is not expected to be released during Francis’ visit.

“We understand the desire to name these texts, acknowledge their impact and renounce the concepts associated with them,” Neil MacCarthy, in charge of communications for the papal visit, told The Associated Press in an email.

Asked about the protest Thursday, MacCarthy said: “We recognize that there are very passionate feelings about a number of issues including the Doctrine of Discovery. The brief peaceful protest did not disrupt the service and the group had a chance to express their concerns.”

The Vatican clearly anticipated that the issue would arise during the trip. In an essay in the current issue of the Vatican-vetted Jesuit journal La Civilta Cattolica, the Rev. Federico Lombardi acknowledged that the issue remains an important one for Indigenous peoples, but stressed that the Holy See’s position in repudiating the discovery doctrine is clear.

Lombardi, the retired Vatican spokesman, cited the subsequent 1538 bull “Sublimis Deus” that asserted that Indigenous peoples cannot be deprived of their freedom or possession of their property “nor should they be in any way enslaved.”

But Philip Arnold, chair of the department of religion at Syracuse University in New York, which sits on Onondaga Nation territory, said the 1538 bull was effectively “a ruse” since it didn’t call for European colonial powers to give back the land they had already claimed, but rather elaborated the “freedom that comes with submission to the Catholic Church and that sponsoring monarch.”

“The Vatican’s role in justifying the Doctrine of Christian Discovery in the 15th century is the origin story of transatlantic slave trade, land theft, and a settler-colonial extractive economies throughout Africa and the Americas,” he said.

Felix Hoehn, a property and administrative law professor at the University of Saskatchewan, said any repudiation of papal bulls or doctrines would have no legal bearing on land claims today, but would have symbolic value.

“The Vatican doesn’t make Canadian law. Courts aren’t bound by papal bulls or anything of that notion but it would be symbolic,” Hoehn said. “It would add moral pressure.”