[2] He also argued that the name of Haab (or Abba) is in fact a family name (Aba) and identified his person with a certain Lucas, who served as provost of Esztergom, then Szepes, and chancellor in the court of Dowager Queen Elizabeth the Cuman from 1280 to 1282.
[5] Haab is first mentioned by contemporary records in the aforementioned charter issued in February 1276, when Matthew II Csák, who functioned as Master of the treasury then, exempted Timothy, Bishop of Zagreb and his chapter from paying the tax pondus (seven denars).
The charter incorrectly refers to Haab as provost of Esztergom, as a result of which the document is considered non-authentic by the Hungarian historiography, but the diploma itself survived only in the 19th-century collection of texts by György Fejér, who may have made a copy error.
During the lawsuit between the Diocese of Veszprém and the Dömös Chapter over the tithe of the three villages of Marót in 1295, Haab was entrusted by Archbishop Lodomer to perform the legal representation of provost Sal Hahót.
[4] For a brief time, he was also involved in the litigation between the Diocese of Veszprém and the convent of the Order of Hospitaller Canons Regular of St Stephen in Esztergom sometime between 1296 and 1298, alongside Herman, the abbot of Pannonhalma.
He was present in the royal council in October 1299, when the monarch returned those castles to the sons of Casimir Hont-Pázmány, which were seized and usurped by Matthew III Csák prior to that during his rebellion.
[12] Following the death of Andrew III and the extinction of the ruling Árpád dynasty in 1301, Haab supported the claim of the young Wenceslaus to the Hungarian throne, along with overwhelming majority of the prelates led by John Hont-Pázmány.
[1] He and other suffragans granted indulgence to the Poor Clares' monastery in Nagyszombat (today Trnava, Slovakia) in July 1301, on their journey to Bohemia in order to invite prince Wenceslaus to become King of Hungary.
In October 1301, the papal legate summoned and convinced the majority of the Hungarian prelates – including Haab – to accept and support the claim of Charles of Anjou, Wenceslaus' rival during the era of interregnum.
[14] Haab attended the national diet in November 1308, summoned by papal legate Gentile Portino da Montefiore, which unanimously proclaimed Charles as king of Hungary.
Haab, along with John III, Bishop of Nyitra, interrogated 14 canons in September 1308, which resulted Peter's confirmation and the excommunication of his rival, cantor Nicholas (the confidant of local oligarch Henry Kőszegi).
[11][16] Haab testified in the summer of 1309 that the powerful oligarch Ladislaus Kán continuously obstructed the work of the legate's staff and the cathedral chapter of Transylvania regarding the investigation of his influence over the church affairs in the province.