While on his deathbed, it is believed that Bogumilus saw a vision of the Virgin Mary and Child, surrounded by a throng of angels, who were inviting him to heaven.

The files were sent to Rome in 1651, however the process was never completed as the Book of Miracles, which was in the hands of a Count, by the name of Sebastian Głębocki, was burned at his court in Głębokie, Kruszwica.

In 1788 a small wooden chapel dedicated to Bogumilus was built, in the wetlands of the Rivers Warta and Teleszyny, near Dobrów, and still stands until this day.

Some scholars believe that Bogumilus is the amalgamation of two historical figures by the names of Bogumił and Piotr, one of whom was the archbishop and the other a monk or the bishop of Poznań.

There is no definitive evidence, to support this, however, and most modern historians regard Bogumił Piotr, as one historical person, who is venerated in the Catholic Church.