Istanbul is a city without equal which has been capital to three empires and straddles two continents. Through it runs the Bosphorus Strait, named “ford of the cow” after the legend of Io, who was transformed into a white heifer by Hera, the jealous wife of Zeus, and escaped across this waterway, which resembles a great winding river. The latest archaeological findings demonstrate that Istanbul is the world’s oldest city to remain constantly inhabited. The text is illustrated by 19th century photographs.