Andrea Gritti

Andrea Gritti was the Doge of Venice from 1523 to 1538, following a distinguished diplomatic and military career.

Gritti was born in Bardolino, near Verona. He spent much of his early life in Constantinople as a grain merchant, looking after Venetian interests. In the late 1490s he was using his commercial correspondence for sending encoded information to Venice regarding the movements of the Turkish navy. In 1499, he was imprisoned on charges of espionage, but escaped execution due to his friendship with the vizier, and was released several years later.

Source: Wikipedia