Controversy still surrounds the sentencing 60 years ago of Julius and Ethel Rosenberg, the only American civilians executed for espionage during the Cold War. Find out about other notorious cloak-and-dagger masters through history, both domestic and foreign.

Mata Hari
The subject of endless speculation and numerous biographies, Mata Hari was a Dutch-born exotic dancer accused of being a German spy during World War I.
Klaus Fuchs
Accused of passing secrets to the Soviets on the design of destructive devices, Klaus Fuchs was a German-born physicist who worked on the Manhattan Project.
Major John André
During the Revolutionary War, the British Army officer persuaded a famous American general to surrender the fort at West Point.
Kim Philby
Handsome and crafty, British intelligence officer Kim Philby was the most successful member of a ring of Soviet agents
Anthony Blunt
Another infamous member of the Cambridge Five, he passed many secrets to the Soviets during World War II and the Cold War.
Guy Burgess
Cambridge was a hotbed of Communist sympathizers during World War II, and Guy Burgess was a student recruited to spy for the Soviets. After joining British intelligence, the double agent passed sensitive information to his Russian "handlers" for many years.
Giacomo Casanova
Born in Italy, Giacomo Casanova traveled throughout Europe in the 18th century, making and losing fortunes with his considerable intellect and famous personal charm. Spying was one of many vocations he practiced.
Nathan Hale
Just a young American young lad at the time of his death (how old was he?), Nathan Hale was a soldier during the Revolutionary War who was caught gathering intelligence behind enemy lines.
Richard Sorge
The man whom one American author called the best spy of all time is almost unknown in the Western world. Some say his intelligence-gathering helped prevent Soviet defeat by the Nazis during World War II.
Alger Hiss
Although he was convicted of spying for the Soviets, American lawyer Alger Hiss maintained his innocence to the end. The truth may never be known.
Valerie Plame
The American CIA operative was outed in 2003 because of her husband's fact-finding mission to Africa
John Walker
The U.S. Naval officer, who once claimed that a big-box store had better security than the Navy, helped the Soviets decode millions of encrypted messages during the Cold War. His ex-wife turned him in when he refused to pay her alimony.
Sir Francis Walsingham
One of the first practitioners of modern espionage, he was a member of a queen's cou
Robert Baden-Powell
The founder of the one of the largest youth organizations was an officer in the British Army and, according to legend, a daring spy as well.
Josephine Baker
The American entertainer, whom a famous author called the most sensational woman he ever saw, also gathered secrets from the Nazis for her adopted country.
Oleg Penkovsky
The Soviet intelligence officer provided John F. Kennedy with critical data about a major arms confrontation. Yet Penkovsky's true colors remain unclear.
Philip Agee
This American CIA agent turned traitor by writing a scandalous book and moving to an island country.