Holy Crown of Hungary in the context of "Regalia"

The Kingdom of Hungary, referred to retrospectively as the Regency, the Horthy era, the Horthy regime, and Horthyist Hungary, existed as a country from 1920 to 1946 under the rule of Miklós Horthy for the most of its existence, who officially represented the Hungarian monarchy after a period of revolutions and the counter-revolution as the Regent of Hungary. In reality there was no king, and attempts by King Charles IV to return to the throne shortly before his death were prevented by Horthy.

Horthy came to power after supressing the Hungarian Soviet Republic during the period of White Terror, installing an authoritarian political system relying on the traditional economic elites and bureaucracy. Hungary under Horthy was characterized by its conservative, nationalist, and fiercely anti-communist character; some historians have described this system as para-fascist. The government was based on an unstable alliance of conservatives and right-wingers; while conservatism was predominant in the 1920s, afterwards Horthy manoeuvered between conservatives and the radical right with fascist leanings. Foreign policy was characterized by revisionism — the total or partial revision of the Treaty of Trianon, which had seen Hungary lose over 70% of its historic territory along with over three million Hungarians, who mostly lived in the border territories outside the new borders of the kingdom, in the Kingdom of Romania and the newly created states of Czechoslovakia and the Kingdom of Serbs, Croats and Slovenes (in greatly enlarged Romania there also remained a significant Hungarian population in Székely Land). Republican Austria, the successor of the former other half of the dual monarchy also received some minor territory from Hungary. Thus the post-1918 kingdom can be described as a rump state. Hungary's interwar politics were dominated by a focus on the territorial losses suffered from this treaty, with the resentment continuing until the present. After a period of international isolation in the 1920s, it began maintaining ties with Fascist Italy and Nazi Germany.

The Lands of the Crown of Saint Stephen (Hungarian: a Szent Korona Országai, lit. 'Countries of the Holy Crown'), informally Transleithania (meaning the lands or region "beyond" the Leitha River), were the Hungarian territories of Austria-Hungary, throughout the latter's entire existence (30 March 1867 – 16 November 1918), and which disintegrated following its dissolution. The name referenced the historic coronation crown of Hungary, known as the Crown of Saint Stephen of Hungary, which had a symbolic importance to the Kingdom of Hungary.

According to the First Article of the Croatian–Hungarian Settlement of 1868, this territory, also called Arch-Kingdom of Hungary (Archiregnum Hungaricum, pursuant to Medieval Latin terminology), was officially defined as "a state union of the Kingdom of Hungary and the Triune Kingdom of Croatia, Slavonia and Dalmatia". Though Dalmatia actually lay outside the Lands of the Crown of Saint Stephen, being part of Cisleithania, the Austrian half of the empire, it was nevertheless included in its name, due to a long political campaign seeking recognition of the Triune Kingdom, which consisted of a united Croatia, Slavonia and Dalmatia.

The King of Hungary (Hungarian: Magyarország királya) was the ruling head of state of the Kingdom of Hungary from 1000 (or 1001) to 1918. The style of title "Apostolic King of Hungary" (Magyarország apostoli királya) was endorsed by Pope Clement XIII in 1758 and used afterwards by all monarchs of Hungary.

John Sigismund Zápolya or Szapolyai (Hungarian: Szapolyai János Zsigmond; 7 July 1540 – 14 March 1571) was King of Hungary as John II from 1540 to 1551 and from 1556 to 1570, and the first Prince of Transylvania, from 1570 to his death. He was the only son of John I, King of Hungary, and Isabella of Poland. John I ruled parts of the Kingdom of Hungary with the support of the Ottoman Sultan Suleiman; the remaining areas were ruled by Ferdinand I of Habsburg, who also ruled Austria and Bohemia. The two kings concluded a peace treaty in 1538 acknowledging Ferdinand's right to reunite Hungary after John I's death, though shortly after John Sigismund's birth, and on his deathbed, John I bequeathed his realm to his son. The late king's staunchest supporters elected the infant John Sigismund king, but he was not crowned with the Holy Crown of Hungary.

Suleiman invaded Hungary under the pretext of protecting John Sigismund from Ferdinand. Buda, the capital of Hungary, fell to the Ottomans without opposition in 1541, but Suleiman allowed the dowager queen, Isabella, to retain the territory east of the river Tisza on John Sigismund's behalf. Isabella and John Sigismund moved to Lippa (now Lipova in Romania). Before long, they took up residence in Gyulafehérvár in Transylvania (Alba Iulia in Romania). John Sigismund's realm was administered by his father's treasurer, George Martinuzzi, who sought to reunite Hungary under the rule of Ferdinand. Martinuzzi forced Isabella to renounce her son's realm in exchange for two Silesian duchies and 140,000 florins in 1551. John Sigismund and his mother settled in Poland, but she continued to negotiate for John Sigismund's restoration with Ferdinand's enemies.

John Alexander Basarab I (Romanian: [basaˈrab] ), also known as Basarab the Founder (Romanian: Basarab Întemeietorul; c. 1270 – 1351/1352), was a voivode and later the first independent ruler of Wallachia who lived in the first half of the 14th century. Many details of his life are uncertain. According to two popular theories, Basarab either came into power between 1304 and 1324 by dethroning or peacefully succeeding the legendary founder of Wallachia, Radu Negru, or in 1310 by succeeding his father, Thocomerius.

A royal charter issued on 26 July 1324 is the first document to reference Basarab. According to the charter, he was subject to Charles I of Hungary as the voivode of Wallachia. Basarab became "disloyal to the Holy Crown of Hungary" in 1325. He seized the Banate of Severin and raided the southern regions of the Kingdom of Hungary. Basarab supported Michael Shishman of Bulgaria's attack against the Kingdom of Serbia, but their united armies were defeated in the Battle of Velbazhd on 28 July 1330. Soon after, Charles I of Hungary invaded Wallachia, but the Wallachians ambushed the royal troops in the Battle of Posada, between the 9 and 12 November 1330, nearly annihilating the entire force, subsequently ending Hungarian suzerainty in Wallachia, allowing the foundation of the first independent Romanian principality. Basarab's descendants ruled Wallachia for at least two centuries. The region of Bessarabia, situated between the rivers Dniester and Prut, was named for the Basarab dynasty.

The coronation of the Hungarian monarch was a ceremony in which the king or queen of the Kingdom of Hungary was formally crowned and invested with regalia. It corresponded to the coronation ceremonies in other European monarchies. While in countries like France and England the king's reign began immediately upon the death of his predecessor, in Hungary the coronation was absolutely indispensable: if it were not properly executed, the Kingdom stayed "orphaned". All monarchs had to be crowned as King of Hungary in order to promulgate laws and exercise his royal prerogatives in the Kingdom of Hungary. Starting from the Golden Bull of 1222, all new Hungarian monarchs had to take a coronation oath, by which they had to agree to uphold the constitutional arrangements of the country, and to preserve the liberties of their subjects and the territorial integrity of the realm.

Ladislaus V, more commonly known as Ladislaus the Posthumous (Hungarian: Utószülött László; Croatian: Ladislav Posmrtni; Czech: Ladislav Pohrobek; German: Ladislaus Postumus; 22 February 1440 – 23 November 1457), was Duke of Austria and King of Hungary, Croatia and Bohemia. He was the posthumous son of Albert of Habsburg with Elizabeth of Luxembourg. Albert had bequeathed all his realms to his future son on his deathbed, but only the estates of Austria accepted his last will. Fearing an Ottoman invasion, the majority of the Hungarian lords and prelates offered the crown to Vladislaus III of Poland. The Hussite noblemen and towns of Bohemia did not acknowledge the hereditary right of Albert's descendants to the throne, but also did not elect a new king.

After Ladislaus's birth, his mother seized the Holy Crown of Hungary and had Ladislaus crowned king in Székesfehérvár on 15 May 1440. However, the Diet of Hungary declared Ladislaus's coronation invalid and elected Vladislaus I as king. A civil war broke out which lasted for years. Elizabeth appointed her late husband's distant cousin, Albert VI as her child's guardian. However, as a representative of the interests of the Austrian and Hungarian estates, he could not defend himself against his older brother and rival, Frederick III, King of the Romans, who in turn took over his role as guardian of Ladislaus. Albert had to renounce his guardianship and in return received the mighty Hungarian border castle Forchtenstein, including a principality in the Hungarian-Styrian-Carinthian area. Ladislaus lived at Frederick's court (mainly in Wiener Neustadt), where Aeneas Silvius Piccolomini (later Pope Pius II) wrote a treatise on his upbringing.