[cloudmountain]

Originally, the sign on the Cross of Jesus had the INRI (Jesu Nazareth Rex Juden) in Latin, the "J" pronounced as a "y." But it was also in Aramaic, Greek and Hebrew (alphabetical).
Why the Latin version stuck I don't know.

[left that other site]

Probably because the rulers of the known world at the time spoke Latin.

Just a theory.