The "Passio" (story of martyrdom) of Saint Caesarius is set in Terracina, harbor town near Rome and Naples, under the pagan emperor Trajan (r. 98–117).

A young man was pampered with material delights and fulfilled in all his wishes for eight months; then he was obliged to mount on a richly harnessed horse, climb up to the summit of city's cliff and throw himself into the void, with the recalcitrant horse, to crash against the rocks and perish in the waves in honour of the god Apollo, as a propitiatory offering for the prosperity of the state and the emperors.

The deacon Caesarius denounced this pagan custom and protested: "Alas for a state and emperors who persuade by tortures and are fattened on the outpouring of blood".

He asked permission to pray: a radiant light blazed down on him, and the pagan consul Leontius was thereupon converted and sought baptism; he died shortly after (October 30).

[3] The 1st of November of the year 107 A.D., Luxurius, governor of the city, tied Caesarius and Julian (a local presbyter) up together in a sack and flung them into the sea, from a cliff called "Pisco Montano".

From the early Christian age, Caesarius of Terracina was the saint chosen for his name to consecrate the places that already belonged to the pagan Caesars to the faith of Christ.

[10][11] The analogy between the name of the saint and that of the rooms called Caesareum or Augusteum, reserved in Roman public buildings for the cult of the emperors, has always been connected with the precise will of the Church to supplant devotion to the deceased sovereigns of Rome (rather important in paganism) with the one more tolerable towards a Christian martyr.

[15] It has been noted that Caesarius's passio revolves around the good health or prosperity (salus) of the Roman Empire, borrowing the overtones of his name to suggest that the well-being of the state rested more solidly on Christian foundations than on its pagan past.

m.") are preserved in Saint Anthony's Chapel in Pittsburgh (Pennsylvania); in St. Martha Church in Morton Grove (Illinois); in St. Joseph Cathedral in Buffalo (New York); in St. Raphael's Cathedral (Dubuque, Iowa); in the Shrine of the Holy Relics in Maria Stein (Ohio); in Basilica of the Sacred Heart (Notre Dame), Indiana; in St Margaret's Chapel, Edinburgh; in a private collection in Gnesen Township, St. Louis County, Minnesota; in Basílica of São Sebastião in Rio de Janeiro; in Paróquia Nossa Senhora das Graças in Caieiras; and in the Manila Cathedral (Philippines).

[31] The tour included sites in Italy, Spain, Mexico, Portugal, France, Corsica, Germany, United States, England, Philippines, Croatia and Slovakia.