Berlin Markus Wolf, the head of communist East Germany's spy program, died Thursday. He was 83.
Wolf, who earned the nickname "the man without a face" for his elusiveness, died in his apartment in Berlin, his stepdaughter Claudia Wall said. The cause of his death, on the 17th anniversary of the fall of the Berlin Wall, was not released.
He planted some 4,000 agents in the West - most famously, placing Guenter Guillaume as a top aide to West German Chancellor Willy Brandt. The agent's unmasking forced Brandt to resign in 1974.
Wolf, who said he spurned a CIA offer of a safe new life in California after the Cold War, managed to steal NATO secrets for the Soviet bloc that could have been decisive if war had broken out in Europe.
Wolf's service was part of East Germany's all-pervasive secret police, the Stasi, which was widely loathed and feared for its huge network of domestic informants.