It started as a protest movement over shutting down a website accused of distributing pirated music.
Today, it has a place in the European Parliament.
Buoyed by a majority of young people and first-time voters in Sweden, the Pirate Party won more than 7 percent of the vote, ensuring at least one seat at the European Union Parliament in Brussels.
The Pirate Party rose to prominence earlier this year by campaigning for the music and movie file-sharing website Pirate Bay.
In April, the website's founders were convicted of copyright violations and given a one-year jail sentence as well as a $3.6 million fine.
But in the wake of that ruling, the site continued to operate and the party tripled its membership base, becoming the third largest in the country.
There is more, however, to Monday's victory than a protest vote and illegal file sharing.
The Pirate Party won the support of the majority of Swedes under the age of 30, a group which traditionally fails to participate in European elections. According to polls, a quarter of their voters have little trust in politicians. Almost a fifth are potential supporters of the extreme right-wing Sweden Democrats, who – as a direct result of the Pirate Party – failed to garner enough support to win a seat.
While the Pirate Bay court case boosted the party's profile, the political climate was already changing in its favor.
"A new conflict over the Internet emerged last year when the government brought in the FRA law, allowing widespread monitoring of telephone and internet communications for national security reasons," says polling analyst Niklas Kaellebring. "Then we had the IPRED (Intellectual Property EU Directive) law from the EU against downloading of copyrighted material earlier this year."
Given that Sweden has one of the world's highest rates of Internet usage, and that close to 2 million Swedes illegally download movies and music, it is perhaps not surprising that a party advocating an unregulated Internet would be popular. However, the Pirate Party has managed to shift the debate from downloading to civil liberties, and established themselves as the defenders of a free Internet – unshackled by the government or supranational (EU) regulation.
All political parties in Sweden jumped on the band wagon during the recent election campaign, declaring varying levels of support for a free Internet, but few managed to convince voters, with the possible exception of the Greens who doubled their level of support.
"The Pirate Party built a very effective Internet-based organization that's had a major impact on public debate in Sweden via blogs, chat forums, and Twitter," says Anders Rydell, author of Piraterna (The Pirates).
"They clearly moved the main focus from file sharing to personal integrity on the Internet. That meant they could successfully attract people concerned that we are headed towards a Big Brother society."
How that success translates to the European level will depend on how good the pirates are at building alliances with like-minded parties across Europe.