Denis of Hungary (, , , , ; c. 1210 – 1268/72), was a Hungarian-born Aragonese knight and nobleman in the 13th century. Born into a prominent family in the Kingdom of Hungary, he escorted Queen Violant of Hungary to the Kingdom of Aragon in 1235, where he settled down and faithfully served James I of Aragon during the Reconquista. Integrating into the local elite, Denis was the eponymous ancestor of the prominent Dionís (Dionisii) noble family. In Canals, Valencia, a street is named after him.
Theories of origin
Hungarian genealogist Mór Wertner was the first scholar in the late 19th century, who connected "Denis of Hungary" with the prominent lord Denis, son of Ampud, who was responsible for the economy policy and acted as key architect of the large-scale financial reforms during the reign of Andrew II of Hungary. He identified them with each other. According to Wertner, after Andrew's son and main opponent, Béla IV ascended the Hungarian throne in 1235, Denis, who fell out of favor in the royal court, escorted his "relative" Violant (also Yolanda), Andrew's youngest daughter, to the Kingdom of Aragon in 1235, where she became the queen consort of King James I of Aragon.
However, according to the contemporaneous Roger of Torre Maggiore's Carmen Miserabile, Denis, son of Ampud was blinded by Béla IV immediately after his coronation, and he died in captivity in the next year. That Denis, who served the Aragonese royal couple, was alive even in 1268, which is also made impossible to identify him with Denis, son of Ampud. Therefore, historian Szabolcs de Vajay claimed Denis had a namesake son, who served as ispán of Szepes County, possibly sometime between 1231 and 1234 or 1235, like previously his father (based on the inscription on the tombstone of his daughter Elizabeth, where Denis was styled as "comes de Cepeз"), who was the first known office-holder of that dignity in Hungary. Vajay refused the former compliance efforts of "Cepeз" with the Csepel Island, a major royal residence and hunting forest. Accordingly he expatriated to Aragon with his queen in 1235, and after his father became a victim of King Béla's political purges, there was no hope for him to return to Hungary. This "Comes Dionysius" was referred to as Queen Violant's relative () in contemporary Aragonese documents. His alleged father Denis, son of Ampud was indeed a relative of the Hungarian royal family: he was a son of Ampud II and an unidentified daughter of Count Berthold III of Andechs, Margrave of Istria. Through the maternal lineage, Denis was the first cousin of Gertrude of Merania, a daughter of Berthold IV and the first spouse of Andrew II of Hungary. Although Violant was born from the second marriage of Andrew (her mother was Yolanda of Courtenay), thus there was no blood relationship between the queen and Denis of Hungary according to this theory, but the knight clearly belonged to a wider kinship of the royal family. Hungarian and Catalan historiography overall accepted Vajay's theory.
In his 2018 study, Hungarian historian Dániel Bácsatyai disputed the above identification based on archival research. A certain cleric Charles, who attended the University of Bologna, was referred to as a nephew of Cardinal Stephen Báncsa in 1264, then a son of "Count Denis of Hungary" in 1269. Consequently, Bácsatyai considered this Denis belonged to the gens (clan) Báncsa and was not related to Denis, son of Ampud. Accordingly, Denis was the brother of Cardinal Stephen Báncsa and was also a son of Orbász Báncsa. Bácsatyai argued the inscription on the tombstone of his daughter Elizabeth, where Denis was styled as "comes de Cepeз" is not necessarily identifiable with Szepes County. He also claimed the mention of kinship relations between Violant and Denis first appear only in the works of 16th-century historian Jerónimo Zurita y Castro. Historian Gergely Kiss, who had previously written the biography of Cardinal Báncsa, accepted Bácsatyai's argument. Kiss analyzed the composition of Báncsa's household (familia) in the Roman Curia, and observed an unusually large proportion of clergy of Spanish nationality, which is due in part to the fraternal relationship with Denis, according to the historian.