Adeste Fideles (Tune)
Adeste Fideles is the usual name for the tune associated with the Christmas hymn O Come, All Ye Faithful. Tune and text (in the Latin original, "Adeste Fideles") are both attributed to John Francis Wade (ca. 1743), an English Catholic living in exile in Rheims, France, in the eighteenth century.
An alternate name for the tune, once prevalent, is Portuguese Hymn, so called because the hymn became known in England through its use at the chapel attached to the Portuguese embassy.