Frederick lived in Utrecht, in the central part of the Netherlands and was the grandson of King Radbon of the Frisians. He studied hard to become a priest and was very prayerful. When he was ordained, Bishop Ricfried put him in charge of newly converted Christians. Frederick taught them about the Catholic faith.
A few years later, he was chosen as bishop of Utrecht. Bishop Frederick got to know the people of his diocese and really cared about them. He gave much importance to missionary work too. In fact, he sent St. Odulf and other brave priests to areas where the people were still pagan and believed in false gods. He wanted them to hear the Good News of salvation.
Because of his position as bishop, Frederick made a few enemies. Emperor Louis' sons asked Bishop Frederick to speak to their stepmother, Empress Judith, about her wicked lifestyle. The bishop corrected her gently but honestly. Unfortunately, the empress did not take the advice well and she grew angry and was insulted.
Another challenge was the pagan people who lived in the northern part of Frederick's diocese called Walcheren. St. Frederick sent priests to bring these people the love of Jesus. Frederick knew the area was dangerous and unfriendly. He kept close to the priests whom he sent. He encouraged them and tried to help the people receive Christianity. But they were not ready to listen in any way. They resented the bishop's concern for them.
St. Frederick continued his work in the diocese with love and care. Then on July 18, 838, after the bishop celebrated Mass, he was quietly making his thanksgiving when two men attacked him with knives. A sentence from Psalm 116 crossed his mind. Slowly, the dying bishop prayed: "I walk before the Lord in the land of the living." A few minutes later he died.
Some say Empress Judith sent the hired killers because she hated the bishop. Others think the people from Walcheren were responsible. The murderers were never caught and punished. But Bishop Frederick is honored as a martyr and a saint.