Sigismund of Luxembourg (15 February 1368 – 9 December 1437) was Holy Roman Emperor from 1433 until his death in 1437. As the husband of Mary, Queen of Hungary, he was King of Hungary and Croatia (jure uxoris) from 1387. He was elected King of Germany (King of the Romans) in 1410, and was also King of Bohemia from 1419, as well as prince-elector of Brandenburg (1378–1388 and 1411–1415). He was the last male member of the House of Luxembourg.
Sigismund was the son of Charles IV, Holy Roman Emperor and his fourth wife Elizabeth of Pomerania. He married Mary, Queen of Hungary in 1385 and was crowned King of Hungary soon after. He fought to restore and maintain authority to the throne. Mary died in 1395, leaving Sigismund the sole ruler of Hungary.
In 1396, Sigismund led the Crusade of Nicopolis but was decisively defeated by the Ottoman Empire. Afterwards, he founded the Order of the Dragon to fight the Turks and secured the thrones of Croatia, Germany and Bohemia. Sigismund was one of the driving forces behind the Council of Constance (1414–1418) that ended the Papal Schism, but which also led to the Hussite Wars that dominated the later period of his life. In 1433, Sigismund was crowned Holy Roman Emperor and ruled until his death in 1437.
Historian Thomas Brady Jr. remarks that Sigismund "possessed a breadth of vision and a sense of grandeur unseen in a German monarch since the thirteenth century". He realised the need to carry out reforms of the empire and the Church at the same time. However, external difficulties, self-inflicted mistakes and the extinction of the Luxembourg male line made this vision unfulfilled. Later, the Habsburgs would inherit this mission and imperial reform was carried out successfully under the reigns of Frederick III and especially his son Maximilian I, although perhaps at the expense of the reform of the Church, partly because Maximilian was not particularly focused on the matter.
In recent years, scholarly interest (especially from East-Central Europe) has grown greatly in the person and reign of Sigismund — the ruler who had gained and led an imperial association almost reaching the size of the later Habsburg Empire — as well as cultural developments associated with his era. The setbacks which have been seen as his major failures (like dealing with the Hussite movement) are now generally considered to be the result of the lack of financial resources and other heavy constraints, rather than personal failings.
Born in Nuremberg or Prague, Sigismund was the son of Charles IV, Holy Roman Emperor and his fourth and final wife, Elizabeth of Pomerania, who was the granddaughter of King Casimir III of Poland and the great-granddaughter of Gediminas, a Grand Duke of Lithuania. He was named after Saint Sigismund of Burgundy, the favourite saint of Sigismund's father. From Sigismund's childhood, he was nicknamed the "ginger fox" (liška ryšavá) in the Bohemian Crown lands on account of his hair colour.
King Louis I of Hungary always had a good and close relationship with Emperor Charles IV, and Sigismund was betrothed to Louis's eldest daughter, Mary, in 1374, when he was six years old and Mary but an infant. The marital project aimed to augment the lands held by the House of Luxembourg. Upon his father's death in 1378, young Sigismund became Margrave of Brandenburg and was sent to the Hungarian court, where he soon learned the Hungarian language and way of life, and became entirely devoted to his adopted country. King Louis named him as his heir and appointed him his successor as King of Hungary.
In 1381, the then 13-year-old Sigismund was sent to Kraków by his eldest half-brother and guardian Wenceslaus IV of Bohemia, to learn Polish and to become acquainted with the land and its people. King Wenceslaus also gave him Neumark to facilitate communication between Brandenburg and Poland.
While Mary was accepted as monarch of Hungary, Sigismund vied for the crown of Poland as well. However, the Poles were unwilling to submit to a German sovereign, nor did they want to be tied to Hungary. The disagreement between Polish landlords of Lesser Poland on one side and landlords of Greater Poland on the other, regarding the choice of the future monarch of Poland, finally ended in choosing the Lithuanian side. The support of the lords of Greater Poland was, however, not enough to give Prince Sigismund the Polish crown. Instead, the landlords of Lesser Poland gave it to Mary's younger sister Jadwiga, who married Jogaila of Lithuania.
On the death of her father in 1382, his betrothed, Mary, became queen of Hungary and Sigismund married her in 1385 in Zólyom (today Zvolen). The next year, he was accepted as Mary's future co-ruler by the Treaty of Győr. However, Mary was captured, together with her mother, Elizabeth of Bosnia, who had acted as regent, in 1387 by the rebellious House of Horvat, Bishop Paul Horvat of Mačva, his brother John Horvat and younger brother Ladislav. Sigismund's mother-in-law was strangled, while Mary was liberated.
Having secured the support of the nobility, Sigismund was crowned King of Hungary at Székesfehérvár on 31 March 1387. Having raised money by pledging Margraviate of Brandenburg to his cousin Jobst of Moravia (1388), he was engaged for the next nine years in a ceaseless struggle for the possession of this unstable throne. The central power was finally weakened to such an extent that only Sigismund's alliance with the powerful Czillei-Garai League could ensure his position on the throne. It was not for entirely selfless reasons that one of the leagues of barons helped him to power: Sigismund had to pay for the support of the lords by transferring a sizeable part of the royal properties. (For some years, the baron's council governed the country in the name of the Holy Crown). The restoration of the authority of the central administration took decades of work. The bulk of the nation headed by the House of Garai was with him; but in the southern provinces between the Sava and the Drava, the Horvathys with the support of King Tvrtko I of Bosnia, Mary's maternal uncle, proclaimed as their king Ladislaus of Naples, son of the murdered Charles II of Hungary. Not until 1395 did Nicholas II Garai succeed in suppressing them. Mary died heavily pregnant in 1395.
To ease the pressure from Hungarian nobles, Sigismund tried to employ foreign advisors, which was not popular, and he had to promise not to give land and nominations to anyone other than Hungarian nobles. However, this was not applied to Stibor of Stiboricz, who was Sigismund's closest friend and advisor. On a number of occasions, Sigismund was imprisoned by nobles, but with the help of the armies of Garai and Stibor of Stiboricz, he was able to regain power.
In 1396, Sigismund led the combined armies of Christendom against the Turks, who had taken advantage of the temporary helplessness of Hungary to extend their dominion to the banks of the Danube. This crusade, preached by Pope Boniface IX, was very popular in Hungary. The nobles flocked in their thousands to the royal standard and were reinforced by volunteers from nearly every part of Europe, the most important contingent being that of the French led by John the Fearless, son of Philip II, Duke of Burgundy. Sigismund set out with 15,000 men and a flotilla of 70 galleys. After capturing Vidin, he camped with his Hungarian armies before the fortress of Nicopolis. Sultan Bayezid I raised the siege of Constantinople and, at the head of 10,000 men, completely defeated the Christian forces in the Battle of Nicopolis fought between the 25 and 28 September 1396. Sigismund returned by sea and through the realm of Zeta, where he ordained the local Montenegrin lord Đurađ II with the islands of Hvar and Korčula for resistance against the Turks; the islands were returned to Sigismund after Đurađ's death in April 1403.The disaster at Nicopolis angered several Hungarian lords, leading to instability in the kingdom. Deprived of his authority in Hungary, Sigismund then turned his attention to securing the succession in Kingdom of Germany and Kingdom of Bohemia, and was recognized by his childless half-brother Wenceslaus IV of Bohemia as Vicar-General of the whole empire. However, he was unable to support Wenceslaus when he was deposed in 1400, and Rupert of Germany, Elector Palatine, was elected King of Germany in his stead.