Robert Biedron on Monday became Poland's first openly gay mayor.

Biedron, who in 2011 became the nation's first openly gay lawmaker in parliament, was elected mayor of the northern city of Slupsk.

The 38-year-old Biedron told the AP that he was proud of the changes that have taken place in the decade since Poland joined the European Union. In 2004, Gay Pride marches were routinely banned.

“I see how fast Polish society has learned its lesson of tolerance,” Biedron said. “So I am very optimistic and happy with Polish society – and proud.”

Mariusz Kurc, editor of Replika, an LGBT advocacy magazine, said 2014 was “a record breaking” year for openly LGBT candidates. In what the media has dubbed the “Biedron effect,” several candidates announced their sexuality before the local elections. Biedron, however, was the only candidate elected.

“These people have enormous courage, in my opinion,” Kurc said.

Biedron has pledged to turn around Slupsk's depressed economy with investments in green energy.