The 2003 Clos du Marquis, a Bordeaux Blend from the St. Julien sub-region of Bordeaux, France, is a noteworthy red wine produced by Clos du Marquis. This vintage stands out for its composition and maturity, having been crafted with 54% Cabernet Sauvignon, 43% Merlot, and a touch of Petit Verdot, according to Robert Parker's Wine Advocate. The wine was harvested between September 11 and 26, 2003, and has a natural alcohol content of 13.3%.

This wine has received positive evaluations from notable reviewers. Robert Parker's Wine Advocate awarded it a score of 91, describing it as "a brilliant effort" and noting its "deep garnet/ruby/plum color" complemented by aromas of bay leaf, black currants, licorice, and lead pencil shavings. The wine is characterized as "deep, full-bodied, rich and fully mature," with a promising drinking window of another 7-8 years from 2014.

Wine Spectator also provided a favorable review, scoring it 90 and highlighting its "very pretty aromas of blackberry currant and licorice." This review praises the wine for its "full-bodied" nature, "velvety round tannins," and "lots of attractive vanilla and berry flavors." The review suggests that the wine is best enjoyed after 2009, indicating its capacity for aging.

Overall, the 2003 Clos du Marquis is recognized for its complexity and maturity, offering a rich blend of flavors and aromas. It reflects its vintage well, with both reviews commending its depth and fullness. This wine is a solid choice for those who appreciate a mature Bordeaux with a balance of fruit and secondary characteristics.