As kosta pointed out it was in use since the end of the sixth century and was "oficially" formalized at the Council of Trent.
In any event whenever it was practiced and wherever it was practiced it was "new". Many Catholics seem to believe the Latin Mass was practiced from the beginning.
True, we have some supposedly failed Catholics on FR who routinely show massive ignorance of the Faith as well. I'll never forget that acapella Church of Christ preacher hurl at me that if English was good enough for Jesus it was good enough for America. And he meant it, too. I don't know how far he was expecting to go, but I was helping (!!!) his mood along in a rather spirited religious debate (heh heh heh).