Who is Ernst Stavro Blofeld from Thunderball and what is their importance?

Blofeld is a villainous mastermind. Although Bond never meets Blofeld during the novel, Blofeld exists behind the scenes, pulling the strings. Blofeld is a cold, callous, ruthless man driven by self-interest. He began his life of crime during World War II, when he sold secrets to both sides of the war. Since then, he has dabbled in every type of crime and now leads the international criminal organization SPECTRE.