Matteo Salvini, who is Italy's Deputy Prime Minister, hosted the conference in Florence under the slogan "Jobs, Security, Common Sense" on Sunday.
The far-right leaders came from Bulgaria, Belgium, Austria, Czech Republic and The Netherlands, where the far-right won the most seats in the recent parliamentary elections.
"Today we present to Italians and all Europeans a different idea of Europe: the Europe of rights, instead of the Europe of cuts," Salvini said.
Marine Le Pen, the former President of France's National Rally group, opened the conference by video address, saying:
"We are movements of democratic and patriotic resistance in the face of a bureaucratic dominant structure, in the face of an arbitrary power."
Dutch far-right leader Geert Wilders, who leads the Freedom Party in the Netherlands, also gave a video address, saying:
“We must guarantee that decisions that concern our nations are made by people who know it and love it best.”
Hungary's prime minister also tweeted his support.
The conference was aimed at getting the elected members of the Identity and Democracy (ID) group in the European Parliament, which includes the League, the Rassemblement National (RN) and the Alternative for Germany (AfD) party, into battle order ahead of the European Parliament elections in June.
"Today in Florence, men and women with common sense and courage have gathered to defeat an enemy that is Europe's first enemy, the Freemason technocrats who want to destroy the identity of our continent," said Salvini from the rostrum.
The meeting also had a domestic political dimension for the League, as it faced the far-right Fratelli d'Italia party of Prime Minister Giorgia Meloni, an ally but above all a great rival of Salvini, who on the other hand is part of the European Conservatives and Reformists Group with the Spanish Vox and the Polish Law and Justice party (PiS).
Speakers from delegations from a dozen European countries took to the podium for two hours to promote their policies.