In 1784 he became Archbishop-Elector of Cologne, living in the archbishopric's seat at Bonn. He remained in that office until his death, meaning that he participated as Elector in the election of his brother Leopold II in 1790 and later that of his nephew Francis II in 1792.
Maximilian Francis succeeded to the title of Elector of Cologne and the related Bishopric of Münster and maintained his noble court in Bonn. A keen patron of music, Maximilian Francis maintained a court orchestra where Ludwig van Beethoven's father was a tenor in the court chapel and played an important role in the early career of Ludwig van Beethoven. The young Beethoven was an employee in his court's musical establishment, where his grandfather, also named Ludwig van Beethoven, had been Kapellmeister.