For the first time since the Second World War, a far-right party has come second in a German national election, a result that will keep it outside government but make it a fearsome opponent of the ruling parties.
The Alternative for Germany, which has morphed since it was founded in 2013 from a party of libertarian economists to an anti-immigration, pro-Russia group, is forecast to have won the backing of one-in-five Germans.
The AfD has little chance of joining the government as the other parties maintain a "fire wall" to keep it out of office, but leader Alice Weidel implied in her victory speech that it was only a matter of time before that changed.
"Our hand remains outstretched to form a government," she told supporters, adding that it would be tantamount to "electoral fraud" if the first-placed conservatives chose to govern with left-wing parties rather than them.
If that happened, she said, "next time we'll come first."
Weidel, the leader of a nativist party that preaches traditional family values while raising her children with a Swiss-based woman of Sri Lankan background, said the AfD was now "a mainstream party".
Once internationally isolated, it now has an ally in the White House, where Donald Trump's adviser Elon Musk, the world's richest person, regularly posts his support.
"It's the most amazing feeling. I've been here since its founding and to see it on 20% is amazing. We'll be kept out of coalition, but as you can see, the conservatives are taking all of our positions," said Gilbert Kalb, an AfD member celebrating at the party's headquarters.
If cheers were slightly muted, that was because, although its vote share doubled since 2021, the result fell short of the more optimistic expectations.
Traditionally a pensioners' party, the AfD made inroads among the young, many of whom have experienced years of sluggish economic growth. Exit poll data indicated 22% of 25-to-34-year-olds voted for the party, compared to 10% of those aged 70 and over.
Ahead of the result, young men in close-fitting suits milled around at the headquarters, drinking beer and eating bratwurst.
The AfD has undergone successive waves of radicalisation since its founding and is today under surveillance by security services as an anti-democratic threat to Germany's constitutional order.
Policies include drastically restricting migration, disbanding the European Union and dropping support for Ukraine in its war with Russia.
One leading figure is regional boss Bjoern Hoecke, twice convicted for shouting slogans of Adolf Hitler's Nazis. Honorary chairman Alexander Gauland has described the Nazis' genocide of Europe's Jews as a lone stain that could not disfigure the glorious sweep of German history.
It became the largest party in Hoecke's home state of Thuringia last year, and did sufficiently well elsewhere that only improbable and tricky coalitions of centre-right and far left could keep them out of office.
Even outside government it reshaped debate away from the "welcome culture" under which former Chancellor Angela Merkel let a million refugees settle in 2015, with all mainstream parties now pledging to tighten immigration controls.
STILL ISOLATED?
Forecasts suggest it will have 23% of seats in parliament, just under the number needed to set up parliamentary committees of inquiry that can summon witnesses and set the news agenda.
In a sign of quite how far outside Europe's mainstream it is, other far right parties, including Marine Le Pen's National Rally, have refused to work with a party that reminds many Europeans of Germany's Nazi past.
Some legislators nurture close ties with Russia and China: one European Parliament member, Petr Bystron is under investigation for taking payment from a Russian-backed disinformation outlet. Another, Maximilian Krah, was suspended after prosecutors said one of his assistants was spying for China.
There are still formidable barriers in its way: its headquarters, next to an African restaurant on a side street in a distant suburb, is far removed from the other parties' imposing central offices because the stigma surrounding the party is so great that no landlord agreed to let to them.
But there are signs its political isolation is crumbling: Weidel received an invitation to Budapest to see Viktor Orban, who praised her as a "brave woman" after she lambasted a journalist for describing her party as far-right.
Other populists such as Italian Deputy Prime Minister Matteo Salvini and Dutch anti-Islam nationalist Geert Wilders offered congratulations on Sunday.
A year ago, the party seemed to be at a low ebb, buffeted by revelations by investigative journalists that several of its most senior members had met at a secret conference outside Berlin to discuss "remigration" - the deportation of non-ethnic German holders of German citizenship.
The president of Germany's Central Jewish Council, Josef Schuster, told Welt newspaper he was shocked at the strength of the AfD's result.
"This should worry all of us, that a fifth of German voters have voted for a party that in at least some of its policies is far-right, and which in its language and ideology seeks clear links with the radical right and neo-Nazism ...," he said.
