From another thread:
FEAST OF THE DAY
In July of 64 more than half of Rome was destroyed by fire. Rumors
blamed the Emperor Nero, but he shifted blame to the Christians and
began to persecute them as punishment. This event is thought to be
the first organized persecution against the Church. The historian
Tacitus, in his Annales, said that a "great multitude" of Christians
were put to death. The Christians were tortured and killed in Nero's
gardens, some were beheaded, some were crucified, and some
were burned alive. Along with the account of Tacitus, there is the
account of Pope St. Clement I who gives some details into the
deaths. Clement's comes from his letter to the Corinthians. It is
thought by many historians that both Peter and Paul were killed in
this persecution.
The holy men and women are also called the “Protomartyrs of Rome.” They were accused of burning Rome by Nero , who burned Rome to cover his own crimes. Some martyrs were burned as living torches at evening banquets, some crucified, others were fed to wild animals. These martyrs died before Sts. Peter and Paul, and are called “disciples of the Apostles. . . whom the Holy Roman church sent to their Lord before the Apostles’ death.”