Saint John Gualbert
Saint John Gualbert was an Italian Roman Catholic saint, the founder of the Vallumbrosan Order.
He fought mainly against simony
At Florence, Archbishop Peter Mezzobarbo, known also as Peter of Pavia, was publicly accused of simoniacal acquisition of the episcopal dignity. He strenuously denied the charge.
The Vallombrosian monks and their Abbot St. John Gualbert were his chief accusers. Both sides agreed to use the judgment of God, or trial by fire, to resolve the issue.
The Abbot St. John Gualbert designated for the test Peter Aldobrandini. Peter calmly walked the narrow path between two raging bonfires, and emerged unharmed.
The archbishop confessed the simony. Pope Alexander II deposed the archbishop.