Rare Seven Years War Map of the Bretagne coastline from Cape Frehel and S. Cast to St. Michael Bay, from Heiden's Americanische urquelle derer innerlichen kriege des bedrängten Teutschlands.
Heiden's work focused on the various theaters of war and strategic points of interest during the Seven Years War between France and Great Britain. The present map focuses on the coast of Bretagne, centered on St. Malo, and include anchorages, shoals and other details.
The focal point of the map is the conflicts between the English and British Fleets at St. Malo and St. Cast, etc. In 1758, the British began planning an expedition to raid St Malo, a fishing and privateer port on the Brittany coast - which would allow the force to remain in the English Channel so it could return home at short notice in case of a French invasion of Britain. On June 1, 1758, the expedition sailed from England, reaching Cancale Bay near St Malo on June 5. That evening the landing craft carrying the soldiers were put ashore. St Malo was situated at the end of a causeway, and it was hoped that the British could cut off the fresh water supply that ran along it.
Once ashore the only immediate opposition they faced was a French artillery battery, which was subdued by the guns of the British warships. The troops then marched towards St Malo, but it soon became apparent they would need to conduct a full-scale siege to take the town - something they did not have the time to do. Instead the British occupied St Servan, a nearby port, and burned 30 privateers and 100 other vessels. Troops were also sent on a reconnisance eastwards towards Dol. They reported the approach of a sizeable French force - and Marlborough decided that it was the right time to withdraw. On June 11 and 12, 1758, the British expedition returned to ship and set sail.
The force remained off St Malo for more than a week, and then sailed along the coast in an attempt to scout out fresh targets. The possibility of an attack on Le Havre or Caen was considered but not followed through. The British then began to focus their attention on Cherbourg in Normandy. However, Bad weather forced them to abort planned landings on June 29 and July 3, and with his force short of water and other provision Marlborough made the decision to return home, and the expedition sailed for Portsmouth.
This expedition was followed by the Battle of St, Cast, which ended poorly for the British and was the last of the so-called "Descents" to the Bretagne Coast.