As a loyal partisan of queen regent Elizabeth, he was an active participant in the feudal anarchy, when groupings of barons fought against each other for supreme power during the minority of king Ladislaus IV.
Nicholas had two brothers, Ladislaus II, who functioned as Voivode of Transylvania and Judge royal twice,[2] and Julius III, who possibly was killed in the 1260s civil war.
In 1272, he is referred to as her vice-chancellor, but it is possible that he already held the office under the direction of chancellor Philip, Bishop of Vác in the queenly court since 1270, when Stephen V ascended the Hungarian throne.
As a supporter of queen dowager Elizabeth, Nicholas Kán became vice-chancellor of the royal court, held the position until February 1273.
When the cathedral chapter of Esztergom convened between 12 February and 1 March, Nicholas Kán's army surrounded the building, locked the canons and deprived them of food and water with the tacit consent of Elizabeth.
As Elizabeth never regained her central position and decayed into nominal regency, Nicholas Kán lost his political influence for years.
[5] According to historian Sándor Hunyadi, Benedict was already elected in February or March 1273, but Nicholas Kán usurped his position by force (see above).
Later Stephen Báncsa, Archbishop of Kalocsa, who acted as de facto head of the Catholic Church in Hungary, summoned an ecclesiastic congregatio in Buda and excommunicated the leaders of the Saxon rebellion, which devastated the province of Transylvania.
Ladislaus IV commissioned Nicholas Kán, who gained significant room for maneuver against Peter Kőszegi in these months, to lead a royal punitive expedition against the Saxons in Szeben region in 1278, in the same time with the defeat of the Geregye dominion in Tiszántúl, while the king launched a massive royal campaign against the Kőszegis in Transdanubia at the same time.
[18] The pope called Nicholas as a "reckless man, who burnt churches, ousted and looted the canons, appropriated the seal of the cathedral chapter in a guilty way, and, in fact, he never asked for confirmation of his election".
[20] Meanwhile, Pope Nicholas sent Philip, Bishop of Fermo, to Hungary to help Ladislaus IV restore royal power and to fill the position of Archbishop of Esztergom.
Philip was willing to release Nicholas from the excommunication in May 1279, if he resign from the title, return the usurped lands and treasures, and leave Hungary for a pilgrimage to Rome.
[15] During the confrontation between Ladislaus and Philip, the Hungarian king fled the capital for Semlak in Temes County (Tiszántúl) and settled among the Cumans.
Some historians argue, when Ladislaus seized and imprisoned Philip of Fermo in early January 1280, one of his main motivations was the desecration of his loyal prelate's grave.