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CHAPTER 1  THE FIRST SPIES

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VENICE: CITY

OF SECRETS

Venice has long been a city of mystery and

secrets. During the Middle Ages, its republican

government—the Council of Ten—prohibited

officials from having contact with foreigners.

Among the city’s citizens, the wearing of masks

to conceal identities was commonplace, and

secret denunciation was actively encouraged.

VALUABLE SECRETS

There was good reason for Venice’s secrecy. It was first and

foremost a trading state, and its specialty was the import of

high-value goods—textiles, porcelain, and spices—from the

East. These were sold on to the rest of Europe for large

profits. Venetian merchants operated across the Middle East

and India, and a few intrepid Venetian adventurers, such as

Marco Polo, even reached China. Along with traded goods,

the merchants brought back information from the Asian

world, most of it unknown in the rest of Europe.

Venice jealously guarded this trade in goods and

knowledge, hiding its activities behind a cloak of secrecy.

Anyone found to have passed on secrets to foreigners

faced severe penalties. On one occasion, a Venetian official

in Constantinople was discovered to be selling intelligence

to a foreign power. He was recalled to Venice and as his

ship neared home, he was thrown overboard to drown

in the Adriatic Sea.

CODED DEVELOPMENT

In the 1460s, the Italian polymath Leon Battista

Alberti conducted a study of codes and

codebreaking. Although he was unaware of the

pioneering work of the Arab scholar al-Kindi,

Alberti also understood the frequency principle

(where some letters are used more than

others) and he developed a cipher based on

polyalphabetic substitution to minimize its

effect. Whereas the simple Caesar cipher kept

to one alphabet per message, Alberti developed

a cipher disk, now known as an Alberti disk,

on which the alphabetic keys were regularly

changed during the coding of the message.

This made it harder to locate common letters—

such as E or S—as they were given different

substitutions whenever the alphabet changed.

Left: An Alberti disk