Complex sentence: In the end of August 866, a Bulgarian mission arrived in Rome, carrying a list of 115 questions by Knyaz Boris, regarding the Christian way of life of the newly converted Bulgarians and the organization of a future Bulgarian Church under Rome's jurisdiction.
Split into simpler sentences: In the end of August 866, a Bulgarian mission arrived in Rome, carrying a list of 115 questions by Knyaz Boris. These had to do with the Christian way of life of the newly converted Bulgarians and the organization of a future Bulgarian Church under Rome's jurisdiction.