King Charles III Heckled by Lidia Thorpe, an Indigenous Australian Senator

King Charles, visiting the former British colony where he retains the ceremonial title of head of state, was shouted at by an Indigenous Australian senator.

Shortly after King Charles III had finished making remarks in Australia’s Parliament on Monday, a voice rang out from the back of the hall. “You are not our king,” shouted Lidia Thorpe, an Indigenous senator and activist for Aboriginal rights. “Give us our land back. Give us what you stole from us.”

As security guards hustled Ms. Thorpe out of the chamber, she continued to heckle the king, demanding that Britain enter a treaty with Australia’s Indigenous population and accusing British colonizers of genocide.

“Our bones, our skulls, our babies, our people,” said Ms. Thorpe, wearing a traditional possum skin cloak and shaking her fist at Charles, as the guards backed her toward the door. “You destroyed our land.”

Once out of the room, Ms. Thorpe could be heard shouting an epithet about the British “colony” in Australia. The king watched impassively from the stage and along with his wife, Queen Camilla, left the reception a few minutes later.

It was a jarring interruption of Charles’s first visit to Australia since becoming king in 2022, and it revived a perennial question about how long the British monarch will reign over Australia. When that question was last put to Australians in 1999, they voted against becoming a republic by 54.8 percent to 45.2 percent.

The republican movement has been largely quiescent since then, though the death of Queen Elizabeth II, a widely revered figure in Australia, fired the hopes of some republicans that it could re-emerge. Anti-monarchy activists have half-jokingly referred to the king’s visit as a “farewell tour.”

Charles is nothing if not a familiar figure in Australia. This is his 17th visit to the country, the most memorable occurring in 1983, when he toured Australia with his first wife, Diana, Princess of Wales. She outshone him at every stop, which she later said caused friction between her and her new husband. While not nearly as celebrated as Diana or his mother, Charles has his fans in the country.

“There’s no personal animosity toward Charles at all,” said Malcolm Turnbull, a former prime minister of Australia, who led the 1999 campaign for a republic. “In fact, he has a lot of admirers in Australia, as he does around the world, not least because of his leadership on environmental issues.”

Speaking in a telephone interview, Mr. Turnbull said the transition from Elizabeth to Charles was nonetheless an appropriate time to revisit the question of a republic. “It’s doable, and if that’s what the people want, we should deliver it,” he said.

But Mr. Turnbull said the republican movement has been hobbled by longstanding divisions over how to elect a head of state, as well as by a compulsory voting requirement that makes it difficult to amend Australia’s constitution.

Last year, the Labour government lost a referendum that would have created an advisory body in Parliament to give Indigenous Australians a greater voice in issues that affect them. The defeat left the government “very bruised,” Mr. Turnbull said, and reinforced the need for it “to pick the right timing” on another republican vote.

Among those who opposed the so-called Voice referendum — saying it did not go far enough in redressing Australia’s colonial-era wrongs — was Ms. Thorpe. She comes from a prominent family of Indigenous activists and has long campaigned for Aboriginal rights and against the British monarchy.

In 2022, when Ms. Thorpe was swearing her oath after having been re-elected to the federal senate, she raised her fist in a Black power salute and referred to the then-queen as “the colonizing Her Majesty Queen Elizabeth II.” She was instructed to repeat the oath and did so in a tone of open mockery.

Buckingham Palace had no response to the heckling incident on Monday. An official at the palace, speaking on condition of anonymity, said, “Their majesties are deeply grateful to the very many thousands who turned out to support them, and are only sorry they didn’t have a chance to stop and talk to every single one. The warmth and scale of the reception was truly awesome.”

For Charles, the trip to Australia is his most ambitious foreign travel since the palace confirmed in February that he had been diagnosed with cancer. The king’s itinerary has been shaped to give him plenty of time for rest and recuperation: After arriving in Sydney on Friday evening, Charles and Camilla took a day off on Saturday, before attending a church service on Sunday.

The king will travel on to Samoa later in the week for a meeting of the heads of government of the Commonwealth. There, he may face further backlash from Britain’s colonial legacy. Caribbean leaders are expected to renew calls for Britain to pay reparations for its role in the slave trade, as well as for damage caused to the islands from climate change.