Towards the end of his life, he appeared in contemporary sources as Demetrius of Vaskút (Hungarian: Vaskúti Demeter), after receiving land donations in Nógrád and Gömör Counties in 1381.

Demetrius, recently created Chancellor of the Kingdom (a post he would hold until his death), had to leave the court having been given the bishopric of Zagreb by Pope Gregory XI on 23 January 1376.

On 16 August 1378, Pope Urban VI appointed him archbishop of Esztergom and made him a cardinal and titular cardinal-priest of Santi Quattro Coronati on 18 October.

As (lord) chancellor, Demetrius was also head of the newly emerged court of special presence (a predecessor institution of the chief justice), however the judicial function was performed by his deputies (the most notable one was John of Küküllő).

[1] Sigismund soon left the kingdom, enabling the Hungarian nobility to invite King Charles III of Naples, the heir male of Louis I, to claim the throne.