The organisation united some 20 groups when it declared its manifesto at the end of 1941.

The organisation is believed to be set up on 26 April 1941, on the day that Adolf Hitler visited the city of Maribor and 20 days after Slovenia, then a part of Yugoslavia, was occupied by Nazi Germany.

But for 20 years the founding meeting was believed to have taken place a day later, a reason why the 27th was declared national holiday. In Socialist-era Yugoslavia, it was celebrated as Day of the Liberation Front.

The founding meeting, held at the home of literary critic Josip Vidmar (1895-1992), was attended by representatives of the Communist Party of Slovenia, the Sokoli gymnastic society, the Christian Socialists and a group of intellectuals.

Although no more than 1,000 in number, the Communists played a decisive role in the Liberation Front. They were well suited to war situation having carried out its activity undercover for two decades after being banned.

The founding groups decided to launch preparations for an armed resistance to liberate and unite Slovenia, a country divided among several occupying forces.

One of its main goals was also to boost the people's morale and the will to fight against the occupying forces, apart from Germany also Italy and Hungary.

It was active through a variety of underground resistance activities such as propaganda leaflets distribution, sabotages, para-military acts and attacks against the occupying forces.

The organisation rapidly gained followers and represented a basis for a Partisan resistance movement, which started forming in the summer of 1941 and later became known as the National Liberation Movement.

The Front ran the National Liberation Movement politically and militarily, historians Zdenko Čepič and Damijan Guštin write in their book "Podobe iz življenja Slovencev v drugi svetovni vojni" (Images from the Lives of Slovenians in WWII).

The movement was active in the entire territory populated by Slovenians, including in Italy, Austria and Hungary, and it gradually started to be dominated by Communists.

While most of the founding groups let the Communists assume the leading role, a fight for internal domination took place in 1942.

The fight ended in March 1943 with the Dolomite Statement, in which the founding members conceded to the Communist Party of Slovenia's views on all basic issues.

Čepič and Guštin say that as the only organisation which decided to immediately organise resistance the front entered "an empty political space".

While traditional political players opposed it for its communist ideology, they did not see it as a rival and underestimated its power to persuade people to resist.

Some of those opposing the Communist leadership of the movement eventually started collaborating with the occupying forces.

However, Čepič and Guštin says anti-communism in Slovenia cannot be equalled with collaboration although many started collaborating because of their opposition of communism.

The most distinctive such group was the Guards (Stražarji), a small but influential Catholic group led by priest Lambert Ehrlich.

But the Liberation Movement continued to spread, becoming so infiltrated that it turned into a kind of a state within a state, especially in Ljubljana.

To protect the movement and its leadership the VOS security and intelligence service was set up at the initiative of the Communist Party of Slovenia.

The movement enjoyed wide support among the people despite clearly expressed political aspirations of the Communists and warnings by politicians that it was just an extension of the Communist Party.