To Agnellus, Bishop of Terracina, on Tree Worship and the Watch on the Walls

Gregory to Agnellus, and so on. [a] It has come to our ears, a thing shocking to report, that some people in your region worship trees and do many other unlawful things contrary to the Christian faith. And we wonder why your fraternity has put off correcting this with strict punishment. For this reason we urge you by this letter to have these people searched out by careful inquiry, and to have such vengeance carried out on them that God may be appeased and their punishment may serve others as a warning example.

We have also written to Maurus the viscount to give your fraternity help in this matter, so that you can have no excuse for not arresting them. Further, since we find that many are excusing themselves from keeping watch on the walls, let your fraternity take care not to allow anyone to be exempted from keeping watch, whether in the name of our church or of yours, or under any other pretext. Let everyone without exception be compelled, so that, with all keeping watch, the guarding of the city may, with the Lord’s help, be better provided for. [b]