It is among the most common given names in Anglophone, Arabic, Persian, Turkish and European countries; traditionally, it was the most common, although it has not been since the latter half of the 20th century. John owes its unique popularity to two highly revered saints, John the Baptist (forerunner of Jesus Christ) and the apostle John (traditionally considered the author of the Gospel of John); the name has since been chosen as the regnal or religious name of many emperors, kings, popes and patriarchs. Initially, it was a favorite name among the Greeks but it flourished in all of Europe after the First Crusade.