[3] On 21 May 1123, Pope Innocent II issued a bull in which the papacy took the church of S. Stefano de Prato under its protection, and granted it various privileges, including the right to the 10% income, the privilege of not having any other church inside its boundaries, the right of burial of its parishioners, and the right not to be subjected to interdict or excommunication without just and reasonable cause.

[4] The pope did, however, emphasize in a letter of 21 December 1133 that the collegiate church was still subject to the bishop of Pistoria, and owed him obedience and reverence, their privileges notwithstanding.

[6] In 1239, the community of Prato, which had been staunchly Guelph in consideration of the many favors obtained from the popes, among them a measure of protection from both Pistoia and Florence, experienced a Ghibbeline revolution and joined the party of the Emperor Frederick II.

[11] The collegiate church of S. Stefano and its Chapter of Canons was suppressed, and in its place the cathedral of S. Stefano was established, administered and served by a corporation called the Chapter, consisting of the Provost, five dignities (the Primicerius, the Archpriest, the Archdeacon, the Dean, and the Treasurer) and nineteen canons.

[13] Duke Ferdinand raised the oppidum of Prato to the rank of civitas in recognition of its greater importance.