Complex sentence: Born in Brescia, Arnold became an Augustinian canon and then prior of a monastery in Brescia became very critical of the temporal powers of Catholic Church that involved it in a land struggle in Brescia against the count-bishop of Brescia.
Split into simpler sentences: Born in Brescia, Arnold became an Augustinian canon and then prior of a monastery in Brescia. He became very critical of the temporal powers of Catholic Church that involved it in a land struggle in Brescia against the count-bishop of Brescia.