Ab urbe condita
Titus Livius (Livy)
Livy. History of Rome, Volumes 1-2. Roberts, Canon, Rev, translator. London, New York: J. M. Dent and Sons; E. P. Dutton and Co., 1912.
He realised that the great necessity of Numa's reign was peace, especially amongst a young and aggressive nation, but he saw, too, that it would be difficult for him to preserve the peace which had fallen to his lot unimpaired. His patience was being put to the proof, and not only put to the proof but despised; the times demanded a Tullus rather than a Numa. Numa had instituted religious observances for times of peace, he would hand down the ceremonies appropriate to a state of war.
In order, therefore, that wars might be not only conducted but also proclaimed with some formality, he wrote down the law, as taken from the ancient nation of the Aequicoli, under which the Fetials act down to this day when seeking redress for injuries. The procedure is as follows: —
The ambassador binds his head in a woollen fillet. When he has reached the frontiers of the nation from whom satisfaction is demanded, he says, “Hear, 0 Jupiter! Hear ye confines”-naming the particular nation whose they are —“Hear, 0 Justice! I am the public herald of the Roman People rightly and duly authorised do I come; let confidence be placed in my words.”
Then he recites the terms of the demands and calls Jupiter to witness: “If I am demanding the surrender of those men or those goods, contrary to justice and religion, suffer me nevermore to enjoy my native land.”