Who is Ernst Stavro Blofeld from On Her Majesty's Secret Service and what is their importance?

Ernst Stavro Blofeld is the villain who James Bond has spent the last year trying to track down. In a previous adventure, Bond foiled Blofeld's plan to blackmail Western governments with nuclear weapons and broke up his criminal organization, SPECTRE. At the beginning of the novel, Bond believes that Blofeld is dead, but he soon finds out that Blofeld has bought a peak in the Alps and is re-forming SPECTRE. Blofeld, probably backed by the Soviet government, is busy planning a biological assault on England's crops, using unwitting girls from Britain's farming communities.