He was born in the 1st century AD and specifically 9 years after the birth of Christ, in the city of Athens and lived the years of the Emperor Domitian. Initially, he was a pagan and due to his high education, he was a member of the “Areopagus” Supreme Court in Athens (hence the name Areopagitis).
According to the Synaxarial tradition, Saint Dionysios traveled to Heliopolis, Egypt, and his journey coincided with the crucifixion of Christ. So, on that Good Friday at the time of the crucifixion, although it was noon, as is well known from the Scriptures, the sun hid and darkness came over all the land. Seeing this phenomenon, Saint Dionysius said: “God suffers or is always despondent” (“God suffers or is lost all”).
When he returned to Athens, he heard the preaching of the Apostle Paul in the Areopagus Hill, who also referred to the supernatural phenomena on the day of the Lord’s crucifixion. Saint Dionysius was immediately convinced of the correctness of Christianity and was baptized with his family.
According to tradition again, when the Saint was informed that the Mother of Christ, Mary, was living in Jerusalem, he went to visit her, as he wanted to meet her. Dionysius traveled a second time to Jerusalem when the Virgin Mary slept.
In Athens, his Christian activity quickly became known, and so it was not long before he was ordained bishop of Athens, succeeding the first bishop, Hierotheos. It seems that St. Dionysius traveled a lot to many parts of the West, where his main concern was the spread of Christianity and the interpretation of the scriptures.
At one point, while in Paris, he, along with his students Rusticus and Eleutherius, were arrested on the orders of the local ruler and beheaded. Some synaxaria writers, of course, disagree with this view and argue that St. Dionysius did not marytr in Paris, without disclosing, however, the exact location of his marytrdom.
Parts of the holy relic of the Saint are kept: in the Docheiariou monastery and the Simonopetra of Mount Athos, in the Dionysiou Monastery of Mount Athos, in the Pantokratoros monastery of Mount Athos, in the Gregoriou Monastery of Mount Athos, in the Monastery of Agios Dionysios in Olympus, in the Monastery of Pantokratora at Ntaou Penteli and in the Monastery of Voulkanos, Messinia.
His memory is normally commemorated on October 3, but after an encyclical of the Holy Archdiocese of Athens (September 1999) it was decided that the memory of the Saint to be honored on October 12 too, when the Synaxis of All Saints of Athens is also honored.