Historical basis for Apostle Peter's death date:
"Ergo abolendo rumori Nero subdidit reos. et quaesitissimis poenis adfecit quos per flagitia invisos vulgus christianos appellabat. Auctor nominis eius christus. Tyberio imperitante per procuratorem pontium pilatum supplicio adfectus erat. repressaque in praesens exitiabilis superstitio rursum erumpebat. non modo per iudaeam originem eius mali. sed per urbem etiam quo cuncta undique atrocia aut pudenda confluunt celebranturque .,. Igitur primum correpti qui fatebantur. deinde indicio eorum multitudo ingens. haud proinde in crimine incendii. quam odio humani generis coniuncti sunt..."
"Therefore, to put an end to the rumor, Nero created a diversion and subjected to the most extraordinary tortures those called Christians, hated for their abominations by the common people. The originator of this name (was) Christ, who, during the reign of Tiberius, had been executed by sentence of the procurator Pontius Pilate. Repressed for the time being, the deadly superstition broke out again not only in Judea, the original source of the evil, but also in the city (Rome), where all things horrible or shameful in the world collect and become popular. So an arrest was made of all who confessed; then on the basis of their information, an immense multitude was convicted, not so much of the crime of arson as for hatred of the human race." --Tacitus's Account of Nero's Persecution of Christians, Annales, 15, 44.2-8 (Tacitus lived from c. AD 56-c. 120; he wrote the Annales after AD 100; he was not a Christian, and is regarded as one of Rome's greatest historians)
Both the pagan historian Tacitus and St. Clement of Rome (the fourth Pope; his papacy was from about 92 to 99 AD) tell of a night of horror (August 15, 64 A.D.) when in the imperial parks Christians were put into animal skins and hunted, were brutally attacked, and were made into living torches to light the road for Nero's chariot.
There was a considerable Jewish population in Rome in the first century, but the Emperor Claudius expelled all Jews from Rome in A.D. 49-50, perhaps due to controversy between Jews and Jewish Christians. (Suetonius, the Roman historian, says that the expulsion was due to disturbances in the city "caused by the certain Chrestus" [Christ].)
Claudius died in 54 AD. Since Paul's Letter to the Romans was addressed to Christians in Rome in the late 50s, it is thought that Christians had returned to the city after Claudius' death.
In July of A.D. 64, more than half of Rome was destroyed by fire. Rumor blamed the tragedy on Nero, who wanted to enlarge his palace.
But Tacitus tells us that he shifted the blame by accusing the Christians.
According to Tacitus, a "great multitude" of Christians were put to death because of their "hatred of the human race."
Peter is thought to have been executed at this time.
Nero, threatened by an army revolt and condemned to death by the Senate, committed suicide in 68 AD at the age of 31.
What was the date of Peter's death?
The brilliant Italian scholar Margherita Guarducci, who passed away several years ago, argued, compellingly, that it was precisely on October 13, 64 AD -- the day of the final apparition at Fatima in 1917.
Guarducci, in a study on this question, wrote: "Tacitus has no hesitation in establishing the year 64 for these events. If we look at the series of events the historian lists as having happened between the fire of Rome (July 18-19) and the end of the year, we can establish that the Vatican spectacles took place in the first half of October. Nor is it difficult to prove that between the end of 64 and Nero's death on June 9, 68, there are no other periods in which there was anti-Christian persecution of the type that Tacitus and Clement describe.
It is also useful to note that the period between the end of September 66 and the beginning of 68 can be excluded without doubt since that was the period of Nero's travels in Greece."
She continues: "But, confirming the dating proposed for the circus spectacles and, therefore, for Peter's martyrdom, are two other important, anonymous, texts in Greek contained in a papyrus conserved in Vienna today. They are the Apocalypse of Peter and the Ascension of Isaiah. I believe that these texts (belonging to the so-called "apocalyptic literature," a very common category between the end of the first century and the first half of the second which used prophetic and symbolic language to interpret historical events of the time) are so well informed on the history of the Neronian period that they must have been written not long after events in 64 (not after the year 80, perhaps).
I also believe that they are the fruit of the same Judeo-Christian environment. After addressing Nero's infamies, the authors of the two texts announce his punishment as imminent. According to the author of the Apocalypse, it would be none other than Peter's martyrdom that would mark the beginning of the emperor's end. This statement is echoed in the Ascension text which affirms that Nero's kingdom would last for "three years, seven months and 27 days" after the apostle's death.
She concludes: "If we calculate three years, seven months and 27 days from Nero's death (June 9, 68), we arrive at the year 64 and October 13 to be precise: this date falls perfectly within the period in which, according to the Tacitus passage, we have set the unleashing of Nero's persecutions."
And she notes: "October 13 was not just any ordinary day. It was the anniversary of Nero's ascent to the throne, his dies imperii. Moreover October 13, 64 was the 10th anniversary of his reign (decennalia), October 13, 54/October 13, 64)... It is highly likely, then, that the Emperor Nero, who loved manifestations to be as spectacular as possible, would have promoted cruel spectacles for his decennalia (a feast when, in the person of the emperor made a god, the majesty of the Roman Empire was exalted). It is highly likely that he would have organized the execution of Christians who were already condemned on charges of being enemies of the empire."
So, it is quite likely that the precise date of Peter's martrydom was October 13, 64 AD.
The blood of martyrs is the seed of the Church.