Updated February 15, 2023 at 1:27 PM ET

Scotland's First Minister Nicola Sturgeon has announced her intention to resign after more than eight years as head of the country's government.

At a press conference at her Edinburgh residence on Wednesday, Sturgeon told reporters she'd wrestled with the decision for weeks, ultimately deciding that someone else would be better suited to the relentless pressure of the job.

"Even if for many across the country and in my party, it might feel too soon, in my head and in my heart, I know that time is now, that it is right for me, for my party, and for the country," Sturgeon said.

"The nature and form of modern political discourse means there is a much greater intensity — dare I say it, brutality — to being a politician than in years gone by," she added.

The decision caught many political observers by surprise. Sturgeon's departure is likely to complicate an issue her party long championed: the Scottish independence movement.

Here's what you need to know.

Why was Sturgeon so instrumental to the independence movement?

It was Scotland's unsuccessful referendum vote in 2014 that led Sturgeon's predecessor, Alex Salmond, to resign. Sturgeon, now 52, was the first woman to lead the country's Scottish National Party (SNP) and serve as first minister.

Sturgeon announced plans for a second referendum vote in 2016 after the United Kingdom voted to leave the European Union.

In June 2022, Sturgeon made a significant move towards independence by asking Boris Johnson, then the U.K. prime minister, for a Section 30 order, which would grant Edinburgh the power to hold such a vote. When Johnson refused, Sturgeon said the SNP would hold a vote anyway.

But this November, the U.K. Supreme Court reaffirmed that the Scottish government cannot hold an independence referendum without U.K. government approval.

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That ruling, combined with the conservative party's hold over the British parliament, had already left the prospect of Scottish independence on shaky ground.

Sturgeon's resignation means the movement is also about to lose its highest-profile supporter.

But on the other hand, a change in leadership could open the door for a new strategy.

If the SNP is going to get any traction, it needs to "relaunch its independence case and start making some bold decisions about what independence really means," said Michael Keating, a professor of politics at University of Aberdeen.

"The question, really, is, will Scotland become a high-taxation, high-spending, pro-welfare, pro-public service like the Nordic countries? Or will it go the direction the rest of the U.K. is going in with a neoliberal model?"

"The problem is that once you start making declarations, you start turning people off," Keating said.

Is Sturgeon resigning because of the gender ID bill?

In the last few months, Sturgeon has been embroiled in a separate fight with the U.K. government over a new law focused on gender identity.

The bill, which aims to make it easier for Scottish residents to legally identify as the gender of their choice on birth certificates, marriage certificates or even a death certification, without undergoing a medical examination.

Hailed by transgender rights activists as a landmark piece of legislation, the bill drew widespread criticism, even from members of Sturgeon's own party.

"We haven't had culture wars in Scotland, but they suddenly arrived with a vengeance," Keating explained.

Most notably, U.K. Prime Minister Rishi Sunak said the law would undermine U.K.-wide legislation because residents in other parts of the Kingdom do need to undergo a medical exam to change their gender. A person could essentially be one gender legally on one side of the Scottish-English border and then another gender legally a mile away.

Sunak used that argument to prevent the bill, which narrowly passed in Scotland's parliament, from becoming a law.

Sturgeon said at the time that Sunak's decision undermined Scotland's democracy, but she felt the political toll personally, registering her "first net negative opinion rating for the first time in eight years," Keating said.

On Wednesday, Sturgeon avoided answering a question about whether the drama was "the straw that broke the camel's back," reiterating instead that she wasn't resigning "over short-term issues."

Was Sturgeon's resignation really such a surprise then?

Despite such heated controversies, just three weeks ago Sturgeon told the BBC there was "plenty left in the tank" and that she hoped to be the very politician who could lead Scotland to independence.

Journalists in the country were surprised to be invited to Sturgeon's residence on short notice during the Scottish parliament's recess. They were even more surprised when Sturgeon delivered a well-crafted, rehearsed resignation speech.

"This decision is not a reaction to short-term pressures. Of course, there are difficult issues confronting the government just now. But when is that ever not the case?" Sturgeon said.

She also acknowledged there would be backlash, saying, "I'm not expecting violins here."

Despite her relative popularity, political experts like Keating say the surprise is in line with predictable political strategies.

"She'd been there for eight years. That's about the shelf life of a politician," the professor said. "In a way, it was a surprise because [she said she was going to go on], but then any leader would say that because you become a lame duck the second you say you're going to resign."

Wait, why are people talking about Jacinda Ardern again?

The suddenness of Sturgeon's departure is drawing comparisons with New Zealand's prime minister, Jacinda Arden, who also announced her surprise resignation last month after five years in office.

Both politicians chose to bow out on their own terms rather than wait to be pushed out. Both referenced the nasty tone of political discourse and the emotional strain that comes with serving in office.

What happens next?

Sturgeon will remain first minister until the Scottish National Party can elect a new leader. She'll continue to serve in parliament until the next election for her seat in May 2026.

As for the independence movement, Sturgeon said on Wednesday that the U.K.'s next election would serve as "a de facto vote" on the feasibility of Scottish independence.

That's when a new British prime minister (and, most likely, one that's not from the conservative party currently in power) might grant Scotland the Section 30 order it needs to hold a fresh vote.

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