Decalogue, Royal Arms. Usually, a Decalogue is a wooden board or boards containing the Ten Commandments, The Apostles Creed, and the Our Father. They were ordered to be displayed in all parish churches shortly after the Reformation, supposedly on the word of Elizabeth I herself. Placed at the east end of the chancel where the altar had formerly been, they were not only to show what were felt to be the only true essentials of the Christian faith, but also of the legal power of the state over the sacramental power of the church. They were sometimes surmounted by the royal arms, although this more commonly took the place of the former rood above the chancel arch.

Very few examples of this age survive. Over the years, they were renewed and repainted; during the Commonwealth period, many sets of royal arms were destroyed, and the puritans also had a cautious eye on some of the words of the Apostles Creed. In practice, most surviving examples in Norfolk churches date from the late 18th and early 19th centuries, at the time of an Evangelical revival. Otherwise, the most unusual Royal Arms are to James II.

The reordering of parish churches under the influence of the Oxford Movement in the second half of the 19th century effectively banished most decalogue boards.

  The royal arms were rehung, usually above the south door, although they survive in their original location some places.

The decalogue boards themselves were placed somewhere inconspicuous, usually high on the west wall, or in the space beneath the tower. In some places, they survive each side of the altar, where an Evangelical vicar would have no truck with Anglo-catholic practices. In other cases, they were simply destroyed.