[1][2] On 15 April 1577, the Diocese of Trujillo was erected by the bull Illius fulciti praesidio of Pope Gregory XIII, taking its territory from the Archdiocese of Lima, of which it was originally a suffragan.

[3] In the communication dated 23 August 1761 by José Antonio Manso de Velasco — the Viceroy of Peru — to his successor, he indicated that the Diocese of Trujillo had 79,114 people in the 7 provinces that then comprised it: Trujillo, Saña, Piura, Caxamarquilla (or Pataz), Caxamarca, Luya and Chillaos, Chachapoyas.

[4] The bishopric also included the governorate of Jaén de Bracamoros, belonging to the Real Audiencia of Quito in the Viceroyalty of New Granada.

[5][6] On 23 May 1943, the Diocese of Trujillo was elevated to the rank of metropolitan archdiocese with the bull Inter praecipuas of Pope Pius XII.

[7] On 17 December 1956 and 4 December 1961, the Archdiocese of Trujillo ceded further portions of territory for the purpose of establishing the Diocese of Chiclayo and the Territorial Prelature of Huamachuco, respectively.