new mass

680
Pope St. Agatho, r. 678-681, spoke out against making changes to the sacramental rites of the Church: “Nothing of the things appointed ought to be diminished; nothing changed; nothing added; but they must be preserved both as regards expression and meaning.” Epistle to the Emperor, apud Labb., ed. Mansi, vol. 2., p 235.

1570
The Council of Trent declared infallible what Agatho said.

​1795
​On August 28, 1795, Pope Pius VI, r. 1775-1799, issued a papal bull, Auctorem fidei, a condemnation of the Synod of Pistoia (1786), which he deemed heretical. In this way, he condemned the New Mass 175 years before it came to be. He lived through the French Revolution.
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For backup, see https://www.youtube.com/watch?v=PaKKKXG4Je4.