[2][3] The name of Pistoia appears for the first time in history in connection with the conspiracy of Catiline (62 BC),[4] but it was only after the sixth century that it became important; it was governed, first, by its bishops, later by stewards of the Marquis of Tuscany.

It was the first to establish its independence, after the death of Countess Matilda, and its municipal statutes were the most ancient of their kind in Italy.

[8] The cathedral, which was dedicated to S. Zeno, was originally administered by a Chapter, composed of twenty-two Canons, led by four ancient dignities; to these four were later added six more.

The dignities included: the Archdeacon, the Dean, the Primicerius, the Treasurer, the Prior, the Sacristan, the Rector, and the Custos.

The matter was settled in an agreement of 27 September 1667, in which it was agreed that the bishop and the Chapter would make appointments alternately.

The Chapter of Prato was composed of five dignities (originally six: the Provost, the Primicerius, the Archpriest, the Archdeacon, the Dean, and the Treasurer) and twenty-six Canons.

[20] In September 1786, Bishop Scipione de' Ricci (1780–1791) held a diocesan synod, and published the constitutions and decrees.

[21] Eighty-five of the propositions in the decrees were condemned by Pope Pius VI in the bull Auctorem fidei of August 28, 1794, four of which were specifically labeled as heretical.