You're my king

The mysterious Dominican friar and papal agent Paul arrives on the scene. At the request of the Czech King John of Luxembourg, he became the bodyguard of his son Charles, the future king and emperor. They meet so that Brother Paul in Pavia, northern Italy, saves 15-year-old Charles from an attempt to poison him. In the following years he is his faithful guide and companion, and also acts as his secret agent and diplomat. It was thanks to the Dominican Paul and his intrigues that Charles, after the death of his father at the Battle of Krescak, got rid of his greatest enemies, the Bavarian Wittelsbachs, and became ruler of the Holy Roman Empire.