- The community of Christian believers throughout the world.
- The territory or countries where Christianity is the dominant religion.
- The collective body of Christian institutions, culture and civilization.
Derived from the words "christ" and "dom" meaning domain, or the realm of the followers of christ.
- The Pope is the spiritual leader of Christendom.
- Christendom was once divided by the East-West Schism.
- The crusades were fought to reclaim the Holy Land for Christendom.
- The medieval Christendom was shaped by the Catholic Church.
- Christendom has faced a decline in the number of followers in recent years.