Poyer begins the Prayer Book of Anne de Bretagne with an image of the Three Persons of the Holy Trinity, which is a fundamental doctrine of Christianity. The picture illustrates the Our Father.

Poyer's Trinity is unusual. Instead of differentiating among the Three Persons: Father, Son, and Holy Spirit, he represents each as a young man with long hair.

Each figure of Poyer's Trinity holds an orb adorned with a cross, signifying Christ's salvation of the world.