In 1955, the wines of Saint-Émilion in the wine-growing region of Bordeaux were classified. Unlike the Bordeaux Wine Official Classification of 1855 covering wines from the Médoc and Graves regions, the Saint-Émilion list is updated every 10 years or so. Following the initial classification, the list was updated in 1969, 1986, 1996, 2006, 2012, and 2022. However the 2006 classification was declared invalid following a series of legal actions, and the 1996 version of the classification has been reinstated for the vintages from 2006 to 2009.
https://en.wikipedia.org/wiki/Classification_of_Saint-%C3%89milion_wine