Nicolas-Alexandre, marquis de Ségur

Nicolas-Alexandre, marquis de Ségur (1695–1755) was a Bordeaux wine maker who during his lifetime was known as the "Prince of Vines" due to his ownership of some of the most famous Bordeaux chateaus-including Château Lafite, Château Latour, Château Mouton and Château Calon-Ségur. A hundred years after his death, the Bordeaux Wine Official Classification of 1855 would designate Lafite and Latour as First Growths, Mouton as a second growth and Calon-Ségur as a third growth.

Nicolas-Alexandre was the son of Alexandre de le Meon de Ségur de Francs et Portugaises and Marie-Thérèse de Clausel and paternal grandson of Jean-Isaac, marquis de Ségur (d. 1707), military commander and a descendant of François de Ségur, seigneur de Sainte-Aulaye (d. 1605). His first cousin was Henri François, comte de Ségur and other relatives include Henri IV, vicomte de Ségur, leader and nobleman, becoming Duke in France and England, and Marguerite de Ségur, HRH Prince Albert's great-grandmother, also Queen Victoria's great-grandmother making Prince Albert and Queen Victoria second if not first cousins, part of Marquessate. The Ségur name has appeared to be in the Royal line from time to time. Through his maternal grandfather, he would inherit Château Latour. In 1716, Alexandre de Ségur bought Château Lafite and following his death, that occurred soon after, the estate passed on to Nicolas-Alexandre. In 1718, he would purchase Château Mouton and Château Calon-Ségur.

At one point he owned the land that would become the classified estates of Chateau d'Armailhac and Chateau Pontet-Canet.

Under the Marquis' influence, the wines of Chateau Lafite became firmly entrenched in the London market. Prime Minister Robert Walpole was a frequent customer, purchasing a barrel every three months. The Marechal de Richelieu introduced the wines of Chateau Lafite to the royal court of Louis XV and spoke glowingly of the wine's invigorating benefits.

Louis gave Nicolas-Alexandre the nickname "The Prince des vignes" when he visited his court. The king mistook the buttons on the Marquis' coat for diamonds and complemented on their quality. The king was then informed that those stones were actually the cut and polished rocks from the Marquis' famous vineyards.

Nicolas-Alexandre is credited with drawing the line that divides the neighboring Chateau Lafite and (now) Chateau Mouton-Rothschild and distinguishing the different styles of wine that these two properties produce. While the other properties were sold not long after his death, Chateau Latour stayed within his family till 1963.