It has been used by David Austin in his breeding program, and is one parent of 'Gertrude Jekyll' . There is some doubt as to whether this is the true 'Comte de Chambord'.
Some authorities believe that it is correctly identified as 'Madame Boll'.
Named after the grandson of Charles X, the last male Bourbon, who would not accept the crown of France and died in exile in 1883. It's got about a half-dozen blooms on it this spring, but they're gorgeous.