[1] The most important Montenegrin Federalist party stronghold was in Katunska nahija, a mountainous region of Old Montenegro including Cetinje, Njeguši, Ćeklići, Bjelice, Cuce, Ozrinići, Rudine, Grahovo, Pješivci, Zagarač and Komani.

[3] During its early years, Montenegrin Federalists cooperated with the Communist Party of Yugoslavia, with common goals of federalisation and obtaining autonomy for Montenegro.

[4] However, after the king's assassination in Marseille in 1934, the new government wanted pacification, so they rehabilitated and released the imprisoned former Green rebel Novica Radović, who became the chief ideologue of the Montenegrin Federalist Party.

Montenegrin Party remained in opposition to every other Yugoslav force after the Cvetković-Maček Agreement in 1939, and anticipated World War II as a way to gain power.

Following the April War and the occupation of Yugoslavia by the Axis forces, Montenegrin Federalist Party offered to collaborate with the Italian Fascists, demanding a "Greater Montenegro" from Neretva river in Herzegovina to Mata in Albania; it would also include Metohija and Sandžak.

A much smaller "Kingdom of Montenegro" was proclaimed on Saint Peter's Day Assembly on 12 July 1941, with the territorial claims of the Ustaše and Albanians being relatively more favoured by the Nazis.

Nicholas' grandson and successor as heir to the throne, Prince Michael of Montenegro, was invited to be its King and head of state, but he vigorously refused claiming that he would not cooperate with Nazis.

A number of party members, headed by Novica Radović, opposed this decision, because the territorial claims were not accepted and it failed to reinstate the Petrović-Njegoš dynasty.

[5] The party split in two factions,[clarification needed] with a most extremist one opposing the new state borders of Montenegro, especially vis-à-vis Albania, and claiming the territory of the Bay of Kotor.