From the 13th century, the Chausey Islands were under French authority, unlike Jersey, 27 miles (45 km) away and under English rule. This labyrinth of islets was perfect for the boats of pirates and privateers who came to hide in the Passe Beauchamp and followed the Sound, a channel running along Grande Île. The wars with Great Britain in the 16th century reinforced the soldiers and privateers prowling around. They often left from Saint-Malo and Dinard, home ports of many of them.