After returning to Belgrade, in September he spoke at a large protest meeting in the Socialist People's Center in Slavija, where the workers adopted the "Resolution on the indivisibility of the Balkans and the need for peace".

[16] The implied expectation was that the occupation forces would show some leniency towards the members of the SSDP, as that was the only party in Europe which voted against a government issuing war bonds in 1914 and that this was preferable to the withdrawal with the rest of the army and the civilian refugees.

[14][15] In the very difficult conditions of the camp, where hunger and scarcity reigned, Filipović gathered around him a group of social democrats from Serbia and, in order to pass the time with Sava Maksimović and Nikola Popović, he organized a foreign language course.

Just a few days after the "Unification Congress" on April 30, 1919, Filip Filipović was mobilized and taken to Thessaloniki via Zaječar and Skopje, and from there via Ohrid and Debar to Piškopeja, a remote village on the border with the Principality of Albania.

[21] In order to publicly compromise the leaders of the revolutionary labor and communist movement, the authorities of the Kingdom of Serbs, Croats and Slovenes arrested them on the charge that they were agents of Bela Kun and Moscow and that they were preparing a Bolshevik coup in Yugoslavia.

In the proposed Program of the Party, Filipović presented the positions of the communists, whose basic lines were the struggle for the Soviet Republic of Yugoslavia; creation of the People's Red Army; expropriation and socialization of production and trade; labor protection; requisition of buildings and apartments; socialization of pharmacies, hospitals and sanatoriums; compulsory education of youth of both sexes; separation of church and state and cancellation of debts and exemption from taxes.

In these elections, in addition to Belgrade, the communists achieved a good result and won the majority in Niš, Kragujevac, Valjevo, Pirot, Šabac, Leskovac, Užice, Uba, Đakovica, Kavadarci and Veles.

By order of the police, only Filipović, Todorović and selected counselors were allowed into the building, to whom the manager of the city of Belgrade, Manojlo Lazarević, announced the decision of the Minister of the Interior, Milorad Drašković, to suspend the newly elected municipal administration.

[36] The Communist Party attached great importance to the elections for the Constituent Assembly, because it was supposed to decide on the form of the state and its internal organization by enacting the Constitution.

Since the KPJ stood for the Soviet Republic of Yugoslavia, it developed a very lively pre-election activity, explaining its views on the organization of the state and highlighting its demands for the improvement of the social position of the working class and the poor peasantry.

In Trbovlje, the miners partially took over power, to which the government responded with brutal terror, and in Ljubljana, on Zaloška Street, on April 24, the gendarmerie shot at the gathered workers, killing 14 and injuring 30.

[41] After the good electoral results achieved by the communists in the municipal and parliamentary elections, as well as various labor strikes, during which there were often clashes with the gendarmerie, the government of the Kingdom of the Serbs, Croats and Slovenes feared the outbreak of a socialist revolution, like those that had broken out in Russia and Hungary.

At the session of the Constituent Assembly on June 11, 1921, on behalf of the Club of Communist Deputies, he made an extensive statement regarding the petition of the Communist Deputies dated June 5, in which it was requested to withdraw the Notice, which illegally took away the right of free action of the KPJ; that all trade union organizations, as well as all workers' centers and socialist printing houses and bookstores, should be allowed to reopen immediately; and that all arrested persons, who were arrested on the basis of the Notice, should be released.

In February 1921, the illegal organization Crvena Pravda ("Red Justice") was founded in Zagreb, whose leadership consisted of Rudolf Hercigonja, Rodoljub Čolaković and Janko Mišić.

Minister Drašković emphasized this in his presentation in the assembly, claiming that the KPJ program adopted at the Vukovar Congress and the draft Constitution of the Kingdom of the Serbs, Croats and Slovenes are mutually irreconcilable.

With the support of the authorities, a group of social democrats and centrists from Serbia and Bosnia and Herzegovina, who left the KPJ after the Second Congress, held a conference in Belgrade at the end of March at which the Socialist Workers' Party of Yugoslavia was formed.

[44] At the end of May, the Government decided to allow trade unions to resume functioning, with the condition that the Ministry of Social Policy would control their operations, so that they do not fall into the hands of the communists again.

This law banned the Communist Party of Yugoslavia, its deputies were excluded from the assembly, and the members of the KPJ Executive Committee were arrested and handed over to the Court, under the pretext that they were responsible for the assassination attempts and murder of Drašković and the preparation of the "Bolshevik revolution".

[52] During his stay in prison, he completed his study "The Development of Society in the Mirror of Historical Materialism", which was the basic literature for the Marxist education of the generations of Yugoslav communists in the interwar period.

In addition to the theoretical introduction to the Marxist laws of the development of human society, the book introduced the readers to the significance of the socialist transformation in Russia and the prospects for the further struggle of the working class.

[55] Upon arrival in Belgrade, at the Sava Pier, Filipović and his companions were greeted by crowds, but also by the gendarmerie, who immediately escorted Kovačević and Ćopić to the train station in order to travel to their hometowns, which were designated as their place of residence.

[58] In October 1923, in Zagreb, he participated with August Cesarec and other left-leaning writers and publicists in founding the newspaper "Književna republika", which was a monthly for cultural issues, whose editor was Miroslav Krleža.

The "Left faction" won the Conference, so the Resolution on the National Question, authored by Đura Cvijić, was adopted and a new leadership led by Triša Kaclerović was elected.

At the end of the same month, he gave a lecture "Knowledge — a weapon of class struggle" in Vračar, and then he participated in the Conference of leather and processing workers, where he spoke about labor legislation.

[61][59] After arriving in Moscow, Filipović first worked in the Red Peasant International, and in March 1926 he was elected a member of the Presidency of the Balkan Communist Conference, whose center was located in Vienna.

[62][63] During his stay in Moscow, Filipović was engaged in theoretical work, and in the newspaper "Communistki International", which was an organ of the Comintern, he wrote small studies on the situation in the KPJ, from its foundation until then.

When applying for admission to the Society of Old Bolsheviks, Filipović attached the recommendation of several former members, among whom were the revolutionaries Karl Daniševski and Yekaterina Gvozdikova-Frumkina, as well as letters of support from Bela Kun and Grgur Vujović.

This purge, followed by arrests, persecution, staged trials and other terror, lasted until the end of 1938, and during it a certain number of prominent Yugoslav communists who were staying in Moscow during those years were killed, among them Kosta Novaković, Sima Marković, Đuro Cvijić, Vladimir Ćopić, Rade Vujović, Kamilo Horvatin and others.

At the Twentieth Congress of the CPSU, held in February 1956, the new leader of the Soviet Union, Nikita Khrushchev, condemned the glorification of the cult of Stalin's personality, as well as the reprisals carried out during the Great Purge.

At the meeting, which was opened by the president of the Central Committee of the SKS, Tihomir Vlaškalić, 47 reports were submitted on the life and revolutionary path and work of the founder and first secretary of the KPJ.