Denis, Palatine of Hungary
[4] Setting in motion again affairs which had been settled, the Hungarians' king dispatched Dionysius, one of the aristocrats of his court who was experienced in many wars, to lay claim to Sirmion with a large army.
Denis is referred to as simply comes (or ispán) in 1162, when Stephen issued his only known royal charter from that year, possibly during his exile or shortly after his return to Hungary in the second half of 1162.
[3] Although Stephen III successfully defended his throne against the Byzantine intervention, he was obliged to renounce Sirmium and Dalmatia in favor of Emperor Manuel following an unsuccessful campaign in 1165.
Henry of Mügeln relates that Stephen III instructed Denis to recover Sirmium for Hungary; in contrast, historian Paul Stephenson considered that the Hungarian king – who, as he argued, had no reason to support the violation of the peace treaty with Manuel – was unable to prevent "the uprising by his disgruntled nobles".
[11][10] The Byzantine campaign caused great devastation in the eastern territories of the Kingdom of Hungary, forcing Stephen III to seek reconciliation and Henry Jasomirgott, Duke of Austria mediated an armistice.
[13] According to John Kinnamos, Denis gathered an army of 15,000 men from 37 counties (their ispáns were also present) with him as commander-in-chief,[14] also recruiting no small number of allied forces as mercenaries, especially Germans [Austrians], as Niketas Choniates writes.
Denis drew his army up in three divisions in a single broad battle line, with infantry drawn up in the centre and behind the cavalry, upon which the Hungarians clearly relied for the effectiveness of their attack.
[18] Following the defeat, Stephen III signed a peace treaty renouncing the duchy – consisted of Sirmium, Croatia, Dalmatia and Bosnia – that their father had bequeathed upon his brother, Béla, who was sent to Constantinople earlier.
[20] Following the death of Stephen III in 1172, Denis, despite their previous antagonism during the Byzantine wars, supported Béla's ascension to the Hungarian throne – whose legitimacy was contested by the youngest brother Géza.
[20] In that year, Denis plausibly participated in the preliminary negotiations to conclude a peace treaty in Venice between Frederick I, Holy Roman Emperor and the pro-papal Lombard League.
After the talks, Christian, Archbishop of Mainz (Frederick's chancellor) requested Patriarch Ulrich II of Aquileia to escort Denis till the Austrian border.
[23] According to historian Gyula Kristó, the bans took charge of the area between the rivers Sava and Drava in the period between 1167 and 1180, since Denis recovered an estate in Varaždin County to the Diocese of Zagreb upon the instruction of Béla III in 1181.
[24] Historian Judit Gál considered after Béla recovered Dalmatia, Hungary's territories beyond the Drava were initially consolidated under a single ban after 1183, during the terms of Denis then Kalán Bár-Kalán.
[3] Historian Attila Zsoldos claimed he is identical with that namesake lord, who served as ispán of Sopron (1197) then Újvár (or Abaúj; 1198–1199) counties, during the reign of Emeric, King of Hungary.
