Günter Guillaume

The rare spy case that brought down a head of government. Guillaume, a Stasi-trained East German agent, posed as a refugee, joined Brandt's Social Democrats and in 1972 became a personal assistant to West German Chancellor Willy Brandt, while Brandt was pursuing closer ties with the East. West German intelligence had advised against his appointment, and intercepted radio messages from East Berlin later put counterintelligence on his trail, yet he stayed close to Brandt until he and his wife, also an agent, were arrested on April 24, 1974. Brandt took political responsibility and resigned two weeks later. Both got long sentences in 1975 and were freed about six years later in an agent swap.