[3] In April 597, following the death of Bishop Bacaudas, Pope Gregory appointed Bishop Agnellus of Terracina as Apostolic Visitor of Formiae, instructing him to summon the clergy and people to elect a successor, and stating that no priest from outside the diocese should be elected, unless no acceptable candidate could be found in the diocese of Formiae.

[6] The remains of S. Marcellus were brought from Syracuse secretly, for the same reason, and hidden in S. Maria del Parco; and, when the secret was revealed in 917, piety and patriotism moved Bishop Bonus and the Hypati, Giovanni and Docibilis, to begin construction of a more suitable and imposing basilica, in the romanesque style, to replace the little S. Maria del Parco.

By way of the Tiber River, the papal party reached Porto, but then had to take to the sea for a rough voyage to Terracina, and from there to Gaeta.

[9] A series of large earthquakes, which began on 1 June 1231, severely damaged buildings from Rome to the Capua, and under Bishop Peter, in 1255, it became necessary to rebuild the cathedral, to which project Pope Alexander IV donated 50 ounces of gold.

[11] A copy of the Bull of Confirmation of Bishop Bartholomew, dated 21 December 1276, provides useful details about the workings of an episcopal election in Gaeta.

On the death of Bishop Benvenuto, the Archpriest and Chapter of Gaeta fixed a date for the election, summoning all who ought to be present and all who wished to attend.

[16] In 1806, Gaeta was occupied by French forces under the command of General Masséna, who had been sent to install Napoleon's brother Joseph as King of Naples.

French laws were applied to the kingdom, which, among other things, meant the abolition of the mendicant Orders, and the reassignment of their churches and convents to civic purposes.

[17] Following the defeat and exile of Napoleon, the Congress of Vienna, and the return of Pope Pius VII from imprisonment in France, it became necessary to restore good order in the Church, and to revise the terms of previous concordats with various European powers.

The Kingdom of Naples proved a difficult case, since its ruler refused to acknowledge the feudal overlordship of the papacy over southern Italy and Sicily.

Finally, after changing its name to "The Kingdom of the Two Sicilies" and repudiating the old feudal subordination, a concordat was signed with King Ferdinand on 16 February 1818, which was ratified by Pope Pius VII on 7 March 1818.

[19] On 27 June 1818 Pius VII, signed the bull "De Utiliori", which carried out the terms of the reorganization of dioceses agreed to in the Concordat.

[23] On 9 February 1849, the Pope was deposed from his political office as sovereign of the Papal States and Rome, since he had abandoned his station.