The territory of the Archdiocese was identical with the Austro-Hungarian County of Gorizia and Gradisca until 1918 when it was transferred to Italy at the conclusion of the First World War.

[2] The first archdeacon was Gerolamo Catta, the parish priest of S. Pietro sull'Isonzo, appointed by the Patriarch Giovanni Grimani on 21 December 1574.

Pope Benedict, in letters of 29 November 1749 and 27 June 1750, invited the two parties to come to an agreement, while for the moment the present arrangements would remain in effect.

[8] The patriarchate of Aquileia was abolished, as Article I of their convention required, and was replaced by two ecclesiastical provinces and two archbishoprics on equal footing: Udine and Gorizia.

[10] In the bull "Sacrosanctae militantis" of 18 April 1752,[11] Pope Benedict established a Chapter to administer the cathedral of The Holy Cross and S. Vitus in Gorizia.

[13] Following the death of the Empress Maria Theresa in 1780, her son Joseph II launched his plans for the reorganization of the churches in Austria, according to an erastian model.

[16] On 4 May 1781, the Emperor promulgated a decree which forbade Austrian bishops from making any use of the papal bull "Unigenitus" of 1711, against Jansenism, or even to allow it to be discussed.

[20] On 27 February 1782, Pope Pius VI departed Rome for Vienna, expecting to negotiate personally with the Emperor Joseph II to settle the differences between the Holy Roman Empire and the Papacy.

On 16 January 1783, the imperial government issued a decree which declared marriage to be a civil contract, subject to complete control by the state, whatever sacramental claims were made with reference to it.

[23] The Austrian plans for the reorganization of dioceses under control of Vienna[24] included the transfer of the metropolitan archbishopric of Gorizia to Ljubljana.

[31] On 27 November 1971, Archbishop Joseph Pogacnick of Ljubljana and Joannes Jenko, the Apostolic Administrator of Gorizia e Gradesca, agreed to a minor exchange of territories.