Done some searching, and came up with:

There is a thread on "Twas on a night like this" here on Mudcat, from 2002. The Folk-Legacy record was done in 1989. Pete Seeger copyrighted his adaptation/translation in 1952.
According to Wikipedia, the original song was written by Alphonsus Maria de Liguori in 1732.
The Springfields' version ("Bambino") is on Youtube.