http://www.dailycatholic.org/leonine.htm
The prayer was written by Leo XIII which is why it is called the Leonine prayer, was done in the 19th century and definitely WAS in Latin. It was tranlated into the vernacular since it was not part of the Mass but said after it. The Last Gospel and other portions were always said in Latin and still are.
Frank
Well, that makes sense. V's wife.