St. John being lowered into the oil.
The tradition which relates
that St. John was miraculously preserved from death
when plunged into a caldron of boiling oil is very ancient,
and is vouched for by Tertullian;
but that this scene took place before the Latin Gate
precisely on the spot where the Church of St. John now stands,
is a conjecture of Ado.

However this may be,
the important fact is the coming of the Apostle John to Rome
some ten years after the martyrdom of Sts. Peter and Paul.
This stational Church of St. John before the Latin Gate i
s the most ancient and venerable monument
which records for the faithful the apostolate at Rome
of the disciple whom Jesus loved so well.