Espionage

Espionage, the use of spies to obtain military and political secrets, is as old as human history. During the Middle Ages, states resorted to espionage from time to time, typically in periods of crisis. However, the development of a permanent system of diplomacy* in the Renaissance changed the nature of espionage. Although ambassadors, the official representatives of foreign governments, had access to a certain amount of information, top-level secrets were rarely shared. Besides, ambassadors were supposed to help countries avoid conflict, not spy on their hosts.

When European states began to establish embassies in rival countries, ambassadors came under considerable suspicion. After all, the main job of ambassadors was to provide information about the host country to their own governments. Some states assigned agents to watch ambassadors to make sure they were not collecting secrets. In Venice members of the government were not even allowed to speak privately with foreign diplomats. But the need for information about the plans and resources of political rivals ensured that spying would occur. Ambassadors and professional spies used whatever methods they could to gather intelligence, including bribing officials and paying informers.

The Protestant Reformation* and religious wars increased international tensions, making spying even more important. Both Catholic and Protestant countries expanded their spy networks as espionage became more elaborate. Bernardino de Mendoza, the Spanish ambassador to England during the reign of ELIZABETH I, recruited a large number of spies locally. He had agents in key ports as well as inside the English government. He used English Catholics to communicate with Mary, queen of Scots (MARY STUART), while she was in prison.

Queen Elizabeth preferred spies to resident ambassadors. Spies were less expensive and usually provided more accurate information. In the late 1500s, the English had the most effective and extensive spy network in Europe. Sir Francis Walsingham, who ran it, gathered agents from all walks of life: noblemen, criminals, and even famous individuals such as the philosopher Giordano BRUNO and the author Christopher MARLOWE. At one time Walsingham had dozens of spies in Spain, France, Germany, Italy, and as far away as Constantinople. At least one of Spain's top spies was actually a double agent working secretly for Walsingham.

Spies were always in danger of being caught, especially through intercepted communications. Agents often sent their messages in diplomatic pouches in the regular mail, but they might disguise the messages by using codes, ciphers (a system of mixing up letters or substituting numbers or symbols), and even invisible ink. Private couriers also carried many communications. Especially sensitive secrets might be sewn into clothing, put into a hidden compartment in a trunk, or memorized and delivered orally so they could not be discovered.