Croatia in union with Hungary in the context of "Sigismund, Holy Roman Emperor"

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.

Demetrius Zvonimir (Croatian: Dmitar Zvonimir, pronounced [dmîtar zʋônimiːr]; Old Church Slavic: ⰸⱏⰲⱏⱀⰻⰿⰻⱃⱏ; died 1089) was a King of Croatia and Dalmatia from 1075 or 1076 until his death in 1089. Prior to that, Zvonimir also served as Ban of Croatia (1064/1070–1074). His native name was Zvonimir, but adopted the forename Demetrius at his coronation.

He first served as ban in the service of King Peter Krešimir IV. Afterwards, Peter Krešimir IV appointed him duke and declared him as his heir. In 1075 or 1076, Demetrius Zvonimir succeeded to the Croatian throne through papal diplomacy. His reign is characterized as relatively peaceful, with no extensive war campaigns, focused instead on Croatia's economic and cultural development. He inherited the Croatian state at its height and ruled from the city of Knin. Medieval legends allege his assassination, but his death and succession are subjects of controversy in historiography. His reign was followed by a period of anarchy, which ended with the ascension of the Hungarian Árpád dynasty and the creation of a union with Hungary.

The Kőszegi (Croatian: Gisingovci) was a noble family in the Kingdom of Hungary and the Kingdom of Croatia in the 13th and 14th centuries. The ancestor of the family, Henry the Great, descended from the gens ("clan") Héder. Henry's paternal great-grandfather was the clan's co-founder Wolfer.

The Palatine of Hungary (Hungarian: nádor or nádorispán, German: Landespalatin, Latin: palatinus regni Hungariae) was the highest-ranking office in the Kingdom of Hungary from the beginning of the 11th century to 1848. Initially, Palatines were representatives of the monarchs, later (from 1723) the vice-regent (viceroy). In the early centuries of the kingdom, they were appointed by the king, and later (from 1608) were elected by the Diet of the Kingdom of Hungary. A Palatine's jurisdiction included only Hungary proper, in the Kingdom of Croatia until 1918 the ban held similar function as the highest office in the Kingdom (after the king himself), monarch's representative, commander of the royal army and viceroy (after the union of Croatia, Slavonia and Dalmatia with Hungary in 1102).

The twelve noble tribes of Croatia (Latin: nobiles duodecim generationum regni Croatie), also known as twelve noble families of Croatia, was a medieval institution of nobility, alliance, or narrow noble community in the Kingdom of Croatia, which can be traced back at least to the 14th century, while the first mention of the institution was in the Pacta conventa document, which is supposedly a later copy of the original from 1102. Regardless of possible earlier references, the first verifiable mention dates from 1350, while the last from 1459. It is considered that by socio-economic power it was composed of lower and middle nobility, which had a privilege of retain and use of heirdom, tax exemption, and limited military obligations to the king. The twelve tribes are Čudomirić, Gusić, Kačić, Kukar, Jamomet, Lasničić, Lapčan and Karinjan, Mogorović, Poletčić, Snačić, Šubić, and Tugomirić.

The House of Zrinski or Zrínyi was a Croatian-Hungarian noble family, a cadet branch of the Croatian noble tribe of Šubić, influential during the period in history marked by the Ottoman wars in Europe in the Kingdom of Croatia's union with the Kingdom of Hungary and in the later Kingdom of Croatia as a part of the Habsburg monarchy. Notable members of this family were Bans of Croatia, considered national heroes in both Croatia and Hungary, and were particularly celebrated during the period of Romanticism, a movement which was called Zrinijada in Croatia.