To get to San Giovanni e Paulo, I walked up the Caelian Hill via an ancient Street called the Clivus Scauri. This was the street in which Pope Gregory the Great grew up in. His parents owned their town house here, which Gregory and his mother eventually turned into a monastery. The peacefullness of what looks like a country road in the middle of Rome, is probably very different to what would have been a very busy street in the 6th century AD.
One imagines that Gregory would have walked from this street towards the river past the Circus Maximus and into the Forum Borarium, where he saw the Saxon children being sold in the slave market and said non Angleli sed angeli! and got the idea of a mission to the island of Britannia. So really one could say that the English church started here.