In 996, the Emperor Otto III confirmed the suffragan status of the diocese of Pedena with regard to the Patriarchate of Aquileia.
[2] On 2 April 1237, Pope Gregory IX wrote to the bishop of Emona (Cittanova) and the bishop-elect of Trieste, expressing his concern that the diocese of Aquileia was far too extensive for the patriarch to administer it adequately, particularly the eastern parts in the neighborhood of Hungary, in which he could not perform visitations.
There were vacancies of pastors and people were dying without being anointed, or were suffering without having sufficient spiritual care, so that they were falling into error.
The two prelates were ordered to investigate the situation of Aquileia and of Pedena, to see whether a mutually agreeable solution to the problems could be worked out.
The bishop of Pedena, Aldrago Antonin de Piccardi had been transferred to the diocese of Senj e Modruš (Croatia) on 14 February 1785, and was not replaced.