Whether it is the time of war or not, spies play an important role in gathering information. However, some spies act as double agents gathering information for the other nations. Here is a list of the top ten spies of the world:
10. Allan Pinkerton
A Scottish detective, Allan was known for his detective techniques some of which are used even today. He shadowed the subjects and using the technique to assume a role, he helped in shaping the modern espionage system. Pinkerton was a close aide of Abraham Lincoln and helped capture several outlaws of the time. He even foiled an assassination bid on Abraham Lincoln.