The participation of Catholics in Indonesia has began since the 1920s. In 1923, Fredericus Soetrisno Harjadi, Ignatius Joseph Kasimo, and others formed the Javan Catholic Political Union. In the political situation of the Dutch East Indies, PPKD joined itself with the Indische Katholieke Partij, a federation of Catholic organization in the Dutch East Indies, which was formed on November 1918. Even though PPKD was more oriented to Javanese nationalism, IKP itself was more oriented to the interests of the Dutch Catholics. This conflict of interest led PPKD to split from the IKP, and on 22 February 1925, PPKD transformed itself into a political party. Later, PPKD would transform its name into the Indonesian Catholic Political Union . Inside the Volksraad, PPKI and IKP were separated from each other. PPKI was located in the left group, a group of political parties in Volksraad consisting of Indonesians, while IKP was located in middle group, which consisted of Dutch. The left group would later formed the Indonesian Political Federation in 1939. During the Japanese occupation of the Dutch East Indies, PPKI was officially abolished by the Japanese. Even though the Japanese officially dissolved PPKI, the executive council of PPKI did not respond to the abolition, and PPKI went underground.
Independence
After the independence of Indonesia on 17 August 1945, Sukarno as the president of Indonesia formed the Central Indonesian National Committee twelve days later. I.J. Kasimo, the chairman of PPKI, was appointed as the member of KNIP. To formalize the representation of PPKI in the committee, PPKI changed its name to the Catholic Party of the Republic of Indonesia on 8 December 1945. During the Indonesia National Revolution, the headquarters of the party was located in Surakarta. By the decision of the council on 11 July 1948, the headquarters was moved to Jogjakarta. In 1948, after the Dutch seize Jogjakarta, PKRI went underground, with its chairman, I.J. Kasimo, working in Sumatra due to his appointment as the Minister of Trade. Other figures from the party which had been appointed as minister are Fredericus Soetrisno Harjadi and Soewarto. The underground hiding ended in the beginning of July 1949 when the Indonesian government returned to Yogyakarta. From 7 until 12 December 1949, PKRI held the All-Indonesian Catholic Congress in Jogjakarta. The congress was attended by delegations from all over Indonesia. The congress discussed about the unity of the Catholic people in Indonesia. The congress also decided to unite all of the Catholic organizations in the United States of Indonesia at that time:
Partai Katolik Indonesia Kalimantan in Kalimantan.
All of the delegations from the organizations agreed to merge into the Catholic Party, which was finalized on 12 December 1949. The first congress of the party was held in Semarang, from 4 until 6 August 1950, on which the Catholic Party decided to move its headquarters into Jakarta.
Membership
Since 1949, Catholic party began to open its membership for non-pribumis, which was based on the decision about the citizenship system of Indonesia, which was established in the Round Table Conference. This decision was reinforced with the approval of the party's constitution in 1950, which stipulates that the terms of membership in the party is: at least 18 years of, a Catholic, and is the citizen of Indonesia. The decision makes the party boasted as one of the first organizations to accept Chinese members and members of European descent.
