Courvoisier and Hennessy are both brands of Cognac. In fact, they are both among the four most famous and most exclusive Cognac brands in the world. Hennessy is the largest producer of Cognac, and was founded in 1765. Courvoisier is the youngest Cognac producer, only founded in 1828, but is also the only Cognac house to win the Prestige de la France award.