Sixty - Ninth Trivia Question

Question

Originally written in Latin, this Christmas hymn

was composed by John Francis Wade in 1743.

The lyrics may have been written as early as the 13th century,

but it seems more likely that they were also written by John Francis Wade.

The original version had four verses, but four more were written –

three by Etienne Jean Francois Borderies, and a fourth written anonymously.

What is the original Latin name of this Christmas hymn

and its English equivalent?