[4] Due to the influence of his cousin, Peter Monoszló, Bishop of Transylvania, Michael was elected Grand Provost by the Transylvanian Chapter in 1287, holding the position until 1296.

[5] In December 1294, Egidius Monoszló donated three villages of the Atyina (today Voćin, Croatia) lordship to the Bő brothers, entrusting the Pécs Chapter to contribute his instruction.

[6] After the death of his predecessor John on 13 October 1295, who presumably supported the Angevins' claim to the Hungarian and Croatian thrones, Michael Bő, a confidant of King Andrew III was elected Bishop of Zagreb.

[3] In the same time, Michael became chancellor (mentioned in 1297) in the court of Andrew's uncle Albertino Morosini, Duke of Slavonia, in addition to his titles of ispán of Garics (Garić or Podgaric) and Gerzence (Garešnica) lordships, held both from 1297 until 1303.

Michael concluded a contract with the Babonići to fought against the Kőszegis, whose troops even plundered and devastated the territory of the Diocese of Zagreb, while looted its treasures.

Its overlord Henry Kőszegi concluded a peace with the Bishop by the end of 1297 and handed over the forts of Gerzence and Garics to the diocese, which suffered from the endless warfare.

[7] In the same year, Michael donated the estate of "Gulynchi" to local noble Ugrin, who proved to be a faithful servant of the bishopric in opposite Grdun (or Gárdony), a "notorious persecutor" of the diocese.

After a group of powerful lords invited Charles of Anjou to the Hungarian throne in early 1300, Andrew III reconciled with his ardent enemies, the oligarchs by the summer of 1300.

[11] While Henry Kőszegi, under his agreement with Andrew III, was installed as Ban of Slavonia, the Babonići drew the Diocese of Zagreb to their sphere of interest with royal approval in the same time.

Following that Michael became one of the first partisans of Charles of Anjou beside Archbishop-elect Gregory Bicskei, while majority of the prelates supported the claims of the Bohemian prince Wenceslaus.

As a skilled notary and canonist, he help the diplomatic work of papal legate Niccolo Boccasini, who tried to persuade the secular barons to support Charles' claim against the other pretenders.

[14] His ally, Archbishop-elect Gregory Bicskei was murdered in Anagni on 7 September 1303 by soldiers whom Philip IV of France had sent to Italy to capture Pope Boniface, who also died in the next month.

There Wenceslaus II of Bohemia called upon Michael to crown his namesake son as King of Hungary, but the Archbishop refused the threat and also resisted attempts at bribery.