Rijeka (Italian and Hungarian: Fiume, Slovenian: Reka, German: St. Veit am Flaum) is the principal seaport of Croatia, located on Kvarner Bay, an inlet of the Adriatic Sea. It was created a free port in 1723 under Habsburg suzerainty. Till the end of WW1 it remained under Hungarian rule as a part of Croatia. Therefore Hungarian stamps were valid there (example). The city had a mixed population, compromising mostly of Croats, Italians and Hungarians. The number of Italians was rising rapidly and in the year 1910 the presented half of the total city population.
After World War I and the demise of Austria-Hungary the question of the status of Rijeka became a major international problem as the city was claimed by both Italy and Croatia. Italy based her claim on the fact that Italians were the largest single nationality within the city and briefly occupied the city in 1918. The first Italian postage stamps for Fiume were issued on 2 December 1918. They were produced by overprinting "FIUME" on the contemporary stamps of Hungary. Both handstamping and printing presses were used (PIC). January also saw the first appearance of an issue produced specifically for Fiume. It consisted of 17 values, ranging from 2 centesmi to 10 corona, and used four designs: a figure representing "Italy", the town clock tower with an Italian flag hanging from it, an allegory of "Revolution", and a sailor raising the Italian flag. The first printings were inscribed just "FIUME", while in July they were redesigned with the inscription "POSTA FIUME", along with other minor changes. Meanwhile, a set of 12 semi-postal stamps was issued 18 May, commemorating the 200th day of peace since the end of the war. Later in 1919 the higher values were surcharged with lower values, and the semi-postals were overprinted "Valore globale" for use as regular stamps (PIC).
At the height of the dispute between the Kingdom of
Serbs, Croats and Slovenes (later the Kingdom of Yugoslavia) and the Kingdom
of Italy, the Powers advocated the establishment of an independent buffer state.
President Woodrow Wilson of the U.S. became the arbiter in the Yugoslav-Italian
dispute over the city. He suggested that Rijeka be set up as an independent
state and as the potential home for the League of Nations organisation.
The dispute led to lawlessness, leading finally to the landing of British and French troops who took over the city. This confusing situation was exploited by the Italian poet Gabriele D'Annunzio who entered the city with his Italian nationalist irregulars on 12 September 1919, forcing the withdrawal of the inter-Allied occupying forces, and began a 15-month period of rule. The plotters sought to have Italy annex Fiume, but were denied. Instead, Italy initiated a blockade of Fiume while demanding that the plotters surrender. D'Annunzio then proclaimed the city to be under the Italian Regency of Carnaro with a constitution foreshadowing much of the later Italian Fascist system, with himself as dictator, with the title of Duce. On 12 September 1920, the 1st anniversary of the city's takeover, the city government issued a series of 14 values featuring a portrait bust of d'Annunzio, intended for regular use, and a set of four with various allegorical designs, intended for the use of the legionnaires on that day only (example).
On 12 November 1920, the Kingdom of Italy and the Kingdom
of Serbs, Croats and Slovenes signed the Treaty of Rapallo by which both parties
agreed to acknowledge "the complete freedom and independence of the State
of Fiume and oblige to respect it for eternity". With this act the "Free
State of Fiume" was created. The newly created state was immediately recognized
by the United States, France and the United Kingdom. D'Annunzio refused to acknowledge
the Agreement and was expelled from the city by Italian Army in December 1920.
The subsequent provisional government overprinted the d'Annunzio heads with
"Governo / Provvisorio". In April 1921 the first parliamentary elections
were held an on 24 April 1921, the 1st constituent assembly overprinted the
semi-postals of 1919 with "24 - IV - 1921" and "Costituente Fiumana".
The following year the 2nd assembly added a "1922" to the overprints
On 3 March 1922 the fascists carried out a coup d'état and the legal government escaped to Kraljevica. On 23 March 1923 a new issue put an end to the flurry of overprints. Its 12 values, inscribed "Posta di Fiume", used four designs, a Venetian sailing ship, a Roman arch, St. Vitus, and a rostral column, all printed over a buff-colored background (PIC).
In January 1924 the Kingdom of Italy and the Kingdom of Serbs, Croats and Slovenes signed the Rome Agreement, agreeing to the annexation of Fiume by Italy and the absorption of Susak by the Serbs; this took effect on 16 March. The government-in-exile of the Free State considered this act invalid and non-binding under international law and continued its activities. After the Treaty of Rome Fiume stamps were overprinted "REGNO / D'ITALIA" (22 February) and then "ANNESSIONE / ALL'ITALIA" (1 March). Some stamps can be seen here. Subsequently Fiume used the stamps of Italy (example).
With the surrender of Italy in the World War II, Rijeka was occupied by Nazi Germany. The communist Yugoslav army liberated the city from German occupation on 3 May 1945, and with the Paris Peace Treaty of 1947, Rijeka and Istria officially became part of Croatia within Yugoslavia. Provisional stamps (overprinted stamps of Socialist Republic of Italy) were used in the area during 1945 and 1946 (PIC). Later regular Yugoslav and Croatian stamps (after 1991) were used in the city.