1,2: 1921 Definitive Set: Prince Alexander and King Peter I (1)
3-5: War Victims Relief Fund (1921)
6: Surcharges on War Victims Issue (1922)
7: 1923 Definitives: King Alexander I (2)
8,9: 1924 Surcharges
10,11: 1924 Definitives
12,13: 1925 Surcharges

 

1: 1926/27 Definitives
2: 1926 Danube Flood Fund Surcharges
3: Cancelled Surcharges (1928)
4-6: Kingdom of Croatia (3) Millenary (1929)
7-9: War Memorial in Paris Fund (1931)
10: 1931 King Alexander Definitive Set (with engraver's name)
11: 1932 King Alexander Definitives (no engraver's name)
12: Overprint of Country's New Name on Kingdom of Croatia Millenary Set (1931)
13: 1932 King Alexander Definitives (with engraver's and drawer's name)

1-6: European Rowing Championships in Belgrade (1932)
7: 11th International Pen Club Congress in Dubrovnik (1933)
8: 1933 Sokols Society Games in Ljubljana: Prince Peter
9: Overprint of Country's New Name on 1926 Definitive Set (1933)

1: Overprint of Country's New Name on 1926 Flood Fund Set (1933)
2: Sokols Society of Sarajevo 20th Anniversary (1934)
3: 1934 Sokols Society of Zagreb 60th Anniversary: Prince Peter in Sokol Uniform
4-8: 1934 Airmail Set
9: 1934 King Alexander Definitives (with engraver's and drawer's name)
10,11: Assassination of King Alexander in Marseille (1934)
12: 1935 King Peter II (4) Definitives
13: King Alexander Assassination First Anniversary (1935)
14: Winter Relief Fund (1935)
15: 1936 Child Welfare Fund: Queen Marie (5)

 

 

(1) Peter Karadjordjevic (1844–1921) became Serbia's first constitutional monarch in the aftermath of the 1903 military coup that resulted in the overthrow of the Obrenovic dynasty, returning from exile to take his place as King.
Peter was born in Belgrade. In the intervening years before his appointment as King, Peter had served with the French during the unsuccessful Franco-Prussian War of 1870–71 and, in 1875, joined the Bosnian insurrection against the Ottomans. The first years of King Peter's reign saw reforms to the constitution, the army and the school system, as well as improvements to the system of agriculture. With the outbreak of war in Europe only a month away, and with Serbia in civil turmoil following the successful outcome of the Balkan Wars, both civil and military authorities demanded that Macedonia be administered by Serbia and in June 1914 Peter passed executive control of government to his second son Alexander, who became Regent on grounds of increasing ill health. With Serbia's defeat towards the close of 1915 at the hands of combined Austro-Hungarian, German and Bulgarian forces, King Peter had to be carried, through the snow-covered mountains of Albania to Corfu.
On December 1, 1918, Peter reappeared briefly to accept his position as monarch of the newly declared Kingdom of the Serbs, Croats and Slovenes, which was to become Yugoslavia. With his death in 1921 his son Alexander became King.

(2) King Alexander I of Yugoslavia (1888–1934) of the Royal House of Karadjordjevic was the first king of the Kingdom of Yugoslavia (1929–34) and before that king of the Kingdom of Serbs, Croats and Slovenes (1921–29).
Alexander Karadjordjevic was born in Montenegro. On 8 June 1922 he married Princess Maria of Romania, the daughter of King Ferdinand of Romania. He spent his childhood in Montenegro, and was educated in Geneva. He continued his schooling at the Military School in St. Petersburg and then in Belgrade. Prince Alexander was not the first in line for the throne but his elder brother, Crown Prince George was considered unstable by most political forces in Serbia and was forced to renounce his claim to throne.
In the Balkan Wars Alexander fought several victorious battles. On 24 June 1914 he became Regent of Serbia. He was also the supreme commander of the Serbian army. In 1915 the Serbian army with the aged King Peter I and Crown Prince Alexander suffered many losses and withdrew through Albania to Corfu, where it was reorganized. After the army was regrouped and reinforced, it achieved a decisive victory on the Thessalonica Frontline. The Serbian army carried out the final operations of the Thessalonica breakthrough in the autumn of 1918.
On the first of December 1918, in a prearranged set piece, Alexander, as Regent, received a delegation of the Peoples Council of the State of Slovenes, Croats and Serbs an address was read out by one of the delegation and Alexander made an address in acceptance. This was considered to the birth of the Kingdom of Serbs, Croats and Slovenes. In 1921, on the death of his father King Peter he inherited the throne of the Kingdom of Serbs, Croats and Slovenes. Dissension and violent turmoil marked the years of the 1920s, as Croat nationalists (among others) protested against Serbian dominance of the newly created state. On 6 January 1929 Alexander abolished the constitution, the national assembly was dissolved, as were the existing political parties and a dictatorship was established. The country was renamed to Yugoslavia. In September 1931 Alexander legalized Yugoslavia's military state. The country was given a new constitution and was divided in administrative districts, following the French model named after rivers. While these measures seemingly were intended to end internal ethnic strife, in reality they meant the implementation of centralization focused on (Serbian) Belgrade. In 1933 Alexander improved relations with Bulgaria and brought Yugoslavia into the Little Entente with Czechoslovakia and Romania, and into the Balkan Entente with Greece, Turkey and Romania, in 1934. Public demand for a return to democratic government grew during 1932 with a downturn in the country's economic position. Alexander was considering restoring a form of parliamentary government when, on 9 October 1934, while on a state visit to France to strengthen the defensive alliance against Nazi Germany, he was assassinated in Marseilles by a Macedonian activist (allegedly acting with Croat separatists). When being driven in a car through the streets along with French Foreign Minister, a gunman, Vlada Georgieff, stepped from the street and shot the King, the Minister and the chauffeur. It was one of the first assassinations captured on film. King Alexander I was buried in the Memorial Church of St. George, built by King Peter I. As his son Peter II was still a minor, Alexander's cousin Pavle Karadjordjevic took the regency of the Kingdom of Yugoslavia.

(3) The first King of Croatia, Tomislav of the Trpimirovic dynasty, was crowned in 925. Tomislav united the Pannonian and Dalmatian duchies and created a sizeable state. The medieval Croatian kingdom reached its peak during the reign of King Petar Kresimir IV (1058-1074).

(4) King Peter II (1923–1970) was the last King of Yugoslavia. He was the son of Alexander I of Yugoslavia and Princess Maria of Romania and Hohenzollern.
He married Princess Alexandra of Greece and Denmark, in London in1944. Their son, Crown Prince Alexander, was born in 1945. His education commenced at The Royal Palace, he then went to Sandroyd School in England, which he left after his father’s assassination in 1934. Peter II succeeded in 1934 after the murder of his father under a regency headed by his father's cousin, Prince Pavle. Although the Regent and his advisors opposed Nazi-Germany, they also feared that if Hitler attacked Yugoslavia, Britain was not in any real position to help. For the safety of the country, they declared that Yugoslavia would adhere to the Tripartite Pact.
On March 27th, 1941 King Peter II was proclaimed of age, and participated in a British-supported coup d'état opposing the Regent's signing the Tripartite Pact. Postponing Operation Barbarossa Germany simultaneously attacked Yugoslavia and Greece. From April 6th, Luftwaffe pounded Belgrade to the ground for three days and three nights. Within a week, Germany, Bulgaria, Hungary and Italy invaded Yugoslavia and the government was forced to surrender on April 17th. King Peter II was forced to leave the country with the Yugoslav Government following the Axes invasion – initially for Greece, Jerusalem and then to Cairo. He came to England in June 1941, where he joined numerous other governments in exile from Nazi occupied Europe. King Peter II completed his education at Cambridge University and joined the Royal Air Force.
Despite the collapse of the Yugoslav army two rival resistance groups to the occupying forces were formed. The first was the Royalist Chetniks led by General D. Mihailovic, the Minister of Defense in the exile government. The other was the revolutionary Partisans led by the communist Josip Broz - Tito. The Allies, having initially supported Mihailovic then threw their support behind Tito. King Peter was deposed after World War II by Yugoslavia's Constituent Assembly on November 29th, 1945, while still in exile. He never abdicated. After the war he settled in the United States. He died in Denver after a failed liver transplant.

(5) Queen Marie of Romania (1900–1961) was wife of King Alexander of Yugoslavia.
She was born in Germany, and was always known by the name Mignon. Her mother was the former Princess Marie of Edinburgh. Though her mother said that Marie's biological father was Grand Duke Boris of Russia, her legal father was her mother's husband, King Ferdinand of Romania, who reluctantly agreed to accept paternity to avoid scandal.
Marie married King Alexander on 8 June 1922 and became Yugoslav Queen Mother when, following the assassination of King Alexander in Marseilles in 1934, her oldest son became Peter II of Yugoslavia, the last Yugoslav king. Mary died in exile in London on 22 June 1961.