Calvados is cider distilled and aged — the benchmark European apple brandy. It carries AOC protection in three tiers: the broad Calvados AOC, the more prestigious Calvados Pays d'Auge (double pot distillation, granted 1942), and Calvados Domfrontais (created 1997, minimum 30% pears) Wikipedia: Calvados.
Two accidents of history gave Calvados a 19th-century golden age. The Little Ice Age damaged grapevines, and then phylloxera (from the 1860s) devastated Europe's vineyards, gutting wine, Cognac and Armagnac supply. Apple spirits filled the gap and Norman orchard acreage expanded dramatically oldliquorsmagazine.com.