Horgan served as B.C.'s New Democrat premier for five years before stepping down in 2022, then was appointed ambassador last year.

But in June, Horgan announced he was on leave from his diplomatic post after being diagnosed with thyroid cancer.

Horgan's family issued a statement on social media saying he died peacefully Tuesday morning at Royal Jubilee Hospital in Victoria.

"The well-being of British Columbia and everyone in it was everything to him. He was surrounded by family and friends and love in his final days."

Horgan is survived by his wife Ellie, and sons Evan and Nate.

Premier David Eby issued a statement saying the news of Horgan's passing leaves him with a heavy heart.

"John loved this province and its people. He sought to address injustice wherever he saw it -- using his time in office to help build a better, stronger British Columbia for everyone," Eby said.

"His many accomplishments as premier will be felt for years and generations to come. His achievements are too numerous to mention, but he was a consequential premier at a critical time in our history. He encouraged all of us to strive to be our better selves."

Horgan, who served five terms as a member of the provincial legislature, resigned his suburban Victoria seat in March 2023, citing health reasons after he received more than 30 radiation treatments to battle throat cancer.

Political scientist Hamish Telford, who teaches at the University of the Fraser Valley, said Horgan accomplished a rarity in politics: he left office more popular than when he was first elected.

Horgan's retirement didn't last long as Prime Minister Justin Trudeau named him Canada's ambassador to Germany in November 2023.

But just six months into his ambassadorial appointment, Horgan announced he had been diagnosed with thyroid cancer after a routine checkup in Berlin for his previous throat cancer.

Horgan had been successfully treated for bladder cancer in 2008.

"I am on leave from my position at the embassy and in hospital receiving immunotherapy to treat this new thyroid cancer," Horgan said in a statement. "It is the third instance of cancer I have had but I remain confident and hopeful that I will again live long and prosper."

The "live long and prosper" comment revealed the former premier's sense of humour was intact, as was his love of science fiction and the TV series "Star Trek."

Horgan will be remembered as a leader whose eight years at the helm of the B.C. New Democrats managed to elevate the party to a pragmatic and steady political force that voters could support after almost 20 years in opposition, said Telford.

"Against the odds, he succeeded and governed for five years and if it wasn't for his health I'm sure he could have kept on governing," Telford said. "He went out more popular than when he came in. That is an extraordinary feat for any politician."

Horgan, known before becoming premier as a take-no-prisoners, often angry opposition politician, transformed into a compassionate, big-hearted, easygoing leader who would say being in government put a spring in his step as opposed to the drudgery of opposition.

"I would say his chief political legacy has been really cementing the NDP for the decade as the party of government," Telford said. "The NDP had only sort of snuck into office previously where there was vote splitting on the right. John Horgan overcame that image of the NDP and planted them very firmly in the middle of the spectrum."

Longtime B.C. New Democrat Mike Farnworth, who knew Horgan as a political colleague and personal friend for more than 30 years, said the former premier convinced voters, and New Democrats themselves, that the party could lead and govern.

"He shattered myths that had often been perpetuated about New Democrats," said Farnworth in an interview before Horgan's death. "They couldn't govern. They couldn't get back-to-back majorities with the same leader. He showed that we could be a governing party and not an opposition party. He showed that we could manage the economy, could govern and we could be a stable majority government."

Farnworth said he viewed Horgan's political legacy as the progress his governments made on reconciliation with First Nations, making history in 2019 when the B.C. Declaration on the Rights of Indigenous Peoples Act became law, and when he helped to steer the province through the COVID-19 pandemic.

But his true legacy was the personal approach he brought to politics, he said.

"His legacy is you can be a decent, genuine individual and you can succeed in politics," Farnworth said. "He's genuine. What you see is what you get and I think that was the secret of his success."

Former BC United house leader Todd Stone had paid tribute to Horgan in the legislature as he left provincial politics, poking fun at the former premier's frequent use of the term "level best."

"John from Langford: all British Columbians thank you for your love of our province, your commitment to serving its people best and thank you for always doing your level best," he said to thunderous applause and laughter.

Horgan, a huge sports fan who kept a lacrosse stick and ball in his office and was a regular, jersey-wearing fan at Victoria Shamrocks lacrosse games, said his love of playing and watching team sports helped him in the political arena.

He was known for taking a team approach to developing government programs and he used skills honed on the basketball court to forge ties with political friends and foes.

The final details of the agreement that produced the NDP minority government in 2017 were agreed upon while Horgan and former Green leader Andrew Weaver sat beside each other at a rugby game in Langford.

Horgan also said he learned to lean on Conservative premiers Doug Ford and Jason Kenney for advice on approaching the federal government on national issues at Council of the Federation gatherings.

He said personal struggles related to his father's death from a brain aneurysm, when Horgan was 18 months old, and his mother's efforts to raise four children opened his heart, especially to society's underdogs.

There were times when his family received food hampers and he was heading down a wrong path as a teenager, Horgan said.

He credited a high school teacher who took him aside and told him to concentrate on sports and academics with turning his life around.

Horgan, known early in his political career for a quick temper, also displayed a sharp sense of humour while premier.

In 2017, during his first visit to Ottawa as premier amid tense confrontations with the federal government over the TMX pipeline from Alberta to B.C., Horgan accidentally knocked over a glass of water at a news conference.

Immediately, he said, "Spills happen."

Trudeau replied, "We'll clean that up."

Horgan said: "Yes you will, it's a federal responsibility."

This report by The Canadian Press was first published on Nov. 12, 2024.