Clos du Marquis, whose first vintage is 1902, originates from the Petit Clos adjoining the Château de Léoville Las Cases, residence of the Marquis de Las Cases. Today, the heart of the Clos du Marquis terroir is mainly located on the Saint-Julien plateau 20 meters above sea level, bordered by famous second growths classified. It is situated 500 meters west of the Grand Enclos de Las Cases. These 40 hectares consist of Quaternary gravels, older and finer than those of the Enclos. In this area, the vineyard is composed of humic podzols over sandy-clay gravels. The significant presence of organic matter on the surface also gives Clos du Marquis its Saint-Julien typicity.

The 2000 vintage was particularly early due to a fairly mild start to the cycle. After abundant rainfall in April and cool weather until mid-June, the summer then became hot and dry until harvest. These very good conditions allowed harvesting perfectly balanced grapes very rich in phenolic compounds.