Pierre-François Guestier (1793-1874) was a Bordeaux wine merchant, French peer and mayor of Saint-Julien. In 1825 he became the owner of Château Beychevelle and its estate of over 250 hectares of land which produced wine, cork, pinewood and wheat. On the estate Guestier set up a stables for thoroughbred horses, known as the Ecurie Guestier. The stables produced a generation of champion thoroughbreds, for which he was elected member of the Jockey Club in Paris.
In 1830 Guestier hosted the Dukes of Aumale and Nemours at a banquet at the Château following the ascension of King Louis-Philippe to the French throne. During the meal a toast was made to 'the best king' and the Dukes, in response, toasted 'the best wine'.
Guestier and his family remained at Beychevelle until he was forced, for financial reasons, to sell the estate in 1874. It sold for 1.6m francs to Armand Heine, a Parisian banker.