At the end of the 17th century, after a succesion of sales, inheritances and marriages, the Latour estate became the property of the Ségur family. It is in 1718 with the Marquis Nicolas-Alexandre de Ségur, that the Great History of the vineyard starts. He was the son of Alexandre de Ségur de Francs and Marie-Thérèse de Clausel, daughter of Joseph de Clausel, the latter being the second husband of Marguerite Coutaut, owner of Château Latour until 1695. Thanks to the marriage of Alexandre de Ségur with Marie-Thérèse de Clausel, "the Tower of Saint-Maubert" entered the Segur family and remained in their hands there for almost 300 years. Just before his death in 1716, Alexandre de Ségur bought Lafite. Two years later, his son, Nicolas-Alexandre, (called "the Prince of Vines") increased the family holding with the acquisition of Mouton (Rothschild) and Calon (Ségur). Only the Margaux estate remained in the hands of the Aulède family. During the first half of the 18 th century, the land of Latour was run in accordance with the possibilities given by the other vineyards of the de Ségur. But in 1755, the death of the Marquis Nicolas-Alexandre created substantial changes in the destiny of Latour : before his death, Lafite was given the most attention among his numerous estates. With the division of the Marquis' personal property, Latour finally received the necessary care and investment it required, and started to develop its full potential during the second half of that century. Because the heirs of the Marquis didn't live in Bordeaux, the administration was necessarily done by a "régisseur" (General Manager) , who had to produce detailed reports on the estate activity. This organization involved complete administration maintenance, culture expenses, and correspondance between the several managers and the owners. This considerable data is a very precious source of information today which helps us to understand the life of the estate during the last 250 years.