Who issued a decree against the use of the "vile and disloyal Gamay" grape, affecting its production location?

The correct choice is based on historical actions taken in the late 14th century. Philip Le Hardi, who was the Duke of Burgundy, issued a decree around 1395 that declared the Gamay grape to be a "vile and disloyal" grape. This decree had significant implications for the production of wine in the Burgundy region, as it sought to improve the reputation and quality of Burgundy wines by favoring the more prestigious Pinot Noir. As a result, the use of Gamay was effectively restricted in favor of the higher-quality varietals that were deemed more suitable for the region's renowned wine production.

This move was part of a broader effort during that period to control the quality of wines produced in Burgundy, ensuring that the wines reflected the distinguished status of the area. It demonstrates the influence of regional leaders on viticulture practices and highlights how specific decrees can shape the landscape of wine production, impacting which grape varieties are cultivated and celebrated.