Sigismund of Luxembourg in the context of "Hedwig of Poland"

Jadwiga (Polish: [jadˈviɡa] ; 1373 or 1374 – 17 July 1399), also known as Hedwig (from German, Hungarian: Hedvig), was the first female monarch of the Kingdom of Poland, as well its last hereditary ruler. She reigned from 16 October 1384 until her death. Born in Buda, she was the youngest daughter of Louis I of Hungary and Poland, and his wife, Elizabeth of Bosnia. Jadwiga was a member of the Capetian House of Anjou, and had forebears among the Polish Piasts.

In 1375, it was planned that when becoming old enough, Jadwiga would marry William of Austria and she lived in Vienna from 1378 to 1380. Louis I is often thought to have regarded her and William as his favoured successors in Hungary after the 1378 death of her eldest sister, Catherine, since the following year the Polish nobility had pledged their homage to Louis' second daughter, Mary, and Mary's fiancé, Sigismund of Luxembourg. However, Louis died, and in 1382, at her mother's insistence, Mary was crowned "King of Hungary". Sigismund of Luxembourg tried to take control of Poland, but the Polish nobility countered that they would be obedient to a daughter of Louis only if she settled in Poland. Queen Elizabeth then chose Jadwiga to reign in Poland but did not send her to Kraków to be crowned. During the interregnum, Siemowit IV, Duke of Masovia, became a candidate for the Polish throne. The nobility of Greater Poland favoured him and proposed that he marry Jadwiga. However, Lesser Poland's nobility opposed him, and they persuaded Elizabeth to send Jadwiga to Poland.

In the Late Middle Ages, the Kingdom of Hungary, a country in Central Europe, experienced a period of interregnum in the early 14th century. Royal power was restored under Charles I (1308–1342), a scion of the Capetian House of Anjou. Gold and silver mines opened in his reign produced about one third of the world's total production up until the 1490s. The kingdom reached the peak of its power under Louis the Great (1342–1382) who led military campaigns against Lithuania, southern Italy and other faraway territories.

The expansion of the Ottoman Empire reached the kingdom under Sigismund of Luxembourg (1387–1437). In the next decades, a talented military commander, John Hunyadi, directed the fight against the Ottomans. His victory at Nándorfehérvár (present-day Belgrade, Serbia) in 1456 stabilized the southern frontiers for more than half a century. The first king of Hungary without dynastic ancestry was Matthias Corvinus (1458–1490), who led several successful military campaigns and also became the King of Bohemia and the Duke of Austria. With his patronage Hungary became the first country which adopted the Renaissance from Italy.

Mary, also known as Maria of Anjou (Hungarian: Anjou Mária, Croatian: Marija Anžuvinska, Polish: Maria Andegaweńska; 1371 – 17 May 1395), reigned as Queen of Hungary and Croatia between 1382 and 1385, and from 1386 until her death. She was the daughter of Louis the Great, King of Hungary and Poland, and his wife, Elizabeth of Bosnia. Mary's marriage to Sigismund of Luxembourg, a member of the imperial Luxembourg dynasty, was already decided before her first birthday. A delegation of Polish prelates and lords confirmed her right to succeed her father in Poland in 1379.

Having no male siblings, Mary was crowned "king" of Hungary on 17 September 1382, seven days after Louis the Great's death. Her mother, who had assumed the regency, absolved the Polish noblemen from their oath of loyalty to Mary in favour of Mary's younger sister, Jadwiga, in early 1383. The idea of a female monarch remained unpopular among the Hungarian noblemen, the majority of whom regarded Mary's distant cousin, Charles III of Naples, as the lawful heir. To strengthen Mary's position, the queen mother wanted her to marry Louis, the younger brother of Charles VI of France. Their engagement was announced in May 1385.

Hrvoje Vukčić Hrvatinić (c. 1350–1416) was a medieval Bosnian nobleman and magnate, Grand Duke of Bosnia, Knez of Donji Kraji, and Duke of Split. He was the most prominent member of the Hrvatinić noble family, and one of the major feudal lords in Kingdom of Bosnia. He was Grand Duke of Bosnia under four Bosnian kings: King Tvrtko I, King Stephen Dabiša, King Stephen Ostoja and King Tvrtko II. In 1403, and after Tvrtko I's death, Ladislaus of Naples named him his deputy for Dalmatia, and bestowed him with a title Duke of Split, later Herzog of Split. He played a crucial role in the dynastic struggles between the Anjou and Luxembourg claimants to the Hungarian-Croatian throne at the end of the 14th century, as well as in the emergence of the Bosnian Kingdom as a regional power during the same period.

Vlad II (Romanian: Vlad al II-lea), also known as Vlad Dracul (Vlad al II-lea Dracul) or Vlad the Dragon (before 1395 – November 1447), was Voivode of Wallachia from 1436 to 1442, and again from 1443 to 1447. He is internationally known as the father of Vlad the Impaler, or Dracula. Born an illegitimate son of Mircea I of Wallachia, he spent his youth at the court of Sigismund of Luxembourg, who made him a member of the Order of the Dragon in 1431 (hence his sobriquet). Sigismund also recognized him as the lawful Voivode of Wallachia, allowing him to settle in nearby Transylvania. Vlad could not assert his claim during the life of his half-brother, Alexander I Aldea, who acknowledged the suzerainty of the Ottoman Sultan, Murad II.

After Alexander Aldea died in 1436, Vlad seized Wallachia with Hungarian support. Following the death of Sigismund of Luxembourg in 1437, Hungary's position weakened, causing Vlad to pay homage to Murad II, which included participating in Murad II's invasion of Transylvania in the summer of 1438. John Hunyadi, Voivode of Transylvania, came to Wallachia to convince Vlad to join a crusade against the Ottomans in 1441. After Hunyadi routed an Ottoman army in Transylvania, the sultan ordered Vlad to come to Edirne where he was captured in 1442. Hunyadi invaded Wallachia and made Vlad's cousin, Basarab II, voivode.