The Moroccan invasion was the direct factor that caused the Songhai kingdom to fall. Many other factors such as incompetent leaders, and loads of rebellions caused this too.
Today, two (2.5) children constitute Americans' ideal family size.
Two children is enough to replicate both parents which means that there will always be a steady number of young and old people in a country. Having two children is ideal - anything below that would result in a smaller population.
Answer
this is gonna be my best educated guess cause i don't have enough information but i think he went back to Rome to build some churches and spread to spread the words of Jesus
The concrete operational stage