The only child of Holy Roman Emperor Sigismund, King of Hungary and Bohemia, Elizabeth was expected to ascend his thrones along with her husband, Albert of Austria.

[6] Her real birth date can be calculated by virtue of a letter of King Sigismund to Kéméndi Péter fia János (John, son of Peter Kemendi), Lord-lieutenant of Zala County dated 26 April 1410 (sabbato post festum s. Georgii) at Végles, Kingdom of Hungary (now Vígľaš, Slovakia) and sealed with Queen Barbara's seal, who also stayed there and in which the king informs him about his daughter's birth alias circa festum beati Francisci confessoris.

The only remaining question, the exact day is educed from the engagement date of his daughter to Archduke Albert, which was held on 7 October 1411, Pozsony,[9] Kingdom of Hungary (now Bratislava, Slovakia, Pressburg in German) and probably may have adjusted to a former important event because it belongs to no religious feasts.

[10] In the end, one concludes that her birth in Prague, on 28 February 1409, similarly to the date of 27 November that year, which in reality was her christening day, is based on false sources.

[18][19] The fact that Elizabeth accompanied her mother into the exile and presumably endured the same harsh treatment despite being recognized as heiress to the throne suggests that Sigismund may have doubted her paternity during that period.

The Habsburgs, Sigismund's longstanding friends and allies, evidently did not question Elizabeth's legitimacy or, at least, were not deterred by the accusations made against her mother.

[21] On 28 September 1421,[16] the enduring friendship between King Sigismund and the House of Habsburg culminated in a marriage treaty signed in Vienna.

[11] The treaty confirmed Elizabeth's status as heiress presumptive of both Hungary and Bohemia but only for as long as she remained Sigismund's only child.

It stipulated that the birth of another daughter would leave Elizabeth with the right to choose one of her father's kingdoms, and the younger sister would inherit the other.

The papal dispensation for the marriage, necessary due to the couple's common descent from Wenceslaus II of Bohemia and Judith of Habsburg, was not sought until 1431, but was easily granted by Eugene IV.

[6] The French travel writer Bertrandon de la Broquière noted that "the Duchess, a tall, handsome woman, daughter to the Emperor, and heiress after him to the kingdoms of Hungary and Bohemia and their dependencies", gave birth to a daughter, "which had occasioned festivals and tournaments that were the more numerously attended because hitherto she had not had any children."

[24] In March 1438, the Imperial Diet elected Albert as Sigismund's successor on the German throne and Elizabeth consequently became queen of the Romans.

Albert was crowned in June, but Elizabeth did not travel to Prague to take part in the ritual and spent the following summer governing Hungary.

[26] Both Komjathy and Andrássy note that although her position as queen-ruler was not questioned, that would not prevent the nobles later from electing a new king because of the belief that a woman would not be strong enough.

By 1440, Elisabeth was the de facto ruling monarch of Hungary, and her orders were respected and carried out though she had not yet been elected by the council and confirmed as such.

Elisabeth left her two younger children in the care of Emperor Frederick III and financed the civil war in Austria.

Her only son Ladislas V the Posthumous of Austria, king of Bohemia and Hungary (born 1440) died without issue, which left the remaining kingdoms of the family to be succeeded by elected rulers.

Her daughters Anna, Duchess of Thuringia (1432–1462), and Elisabeth, Queen of Poland (1437–1505), continued the family which afterwards regained some of these kingdoms.