O Come All Ye Faithful
Come and behold Him
O come let us adore Him,
This appears on Christmas with You.
(John Wade, John Reading)
The text to the Carol O Come All Ye Faithful was originally written in Latin (Adeste Fideles) and was intended to be a hymn, it is attributed to John Wade, an Englishman. The music to O Come All Ye Faithful was composed by fellow Englishman John Reading in the early 1700s. The tune was first published in a collection known as "Cantus Diversi" in 1751. In 1841 Rev. Frederick Oakley is reputed to have worked on the familiar translation of O Come All Ye Faithful which replaced the older Latin lyrics "Adeste Fideles".
source - http://www.carols.org.uk