A ' is a proprietary blended wine (usually a Champagne) that is considered to be the top of a producer's range. Famous examples include Louis Roederer's Cristal, 's ', 's Dom Pérignon, Duval-Leroy's ', Armand de Brignac "Gold Brut", and Pol Roger's '. Perhaps the first publicly available prestige ' was Moët & Chandon's Dom Pérignon, launched in 1936 with the 1921 vintage. Until then, Champagne houses produced different ' of varying quality, but a top-of-the-range wine produced to the highest standards (and priced accordingly) was a new idea. In fact, Louis Roederer had been producing Cristal since 1876, but this was strictly for the private consumption of the Russian tsar. Cristal was made publicly available with the 1945 vintage. Then came Taittinger's ' (first vintage 1952), and 's ' in 1960, a blend of three vintages (1952, 1953, and 1955) and 's '. In the last three decades of the 20th century, most Champagne houses followed these with their own prestige ', often named after notable people with a link to that producer and presented in non-standard bottle shapes (following Dom Pérignon's lead with its 18th-century revival design).