French frigate L'Escarmouche

Laying the keel or laying down is the formal recognition of the start of a ship's construction. It is often marked with a ceremony attended by dignitaries from the shipbuilding company and the ultimate owners of the ship.

The Royal Navy (RN) is the United Kingdom's naval warfare force. Although warships were used by English and Scottish kings from the early medieval period, the first major maritime engagements were fought in the Hundred Years' War against France. The modern Royal Navy traces its origins to the early 16th century; the oldest of the UK's armed services, it is consequently known as the Senior Service.

The English Channel, also known as simply the Channel, is an arm of the Atlantic Ocean that separates Southern England from northern France. It links to the southern part of the North Sea by the Strait of Dover at its northeastern end. It is the busiest shipping area in the world.

Utah, commonly known as Utah Beach, was the code name for one of the five sectors of the Allied invasion of German-occupied France in the Normandy landings on June 6, 1944 (D-Day), during World War II. The westernmost of the five code-named landing beaches in Normandy, Utah is on the Cotentin Peninsula, west of the mouths of the Douve and Vire rivers. Amphibious landings at Utah were undertaken by United States Army troops, with sea transport, mine sweeping, and a naval bombardment force provided by the United States Navy and Coast Guard as well as elements from the British, Dutch and other Allied navies.

Omaha Beach was one of five beach landing sectors designated for the amphibious assault component of Operation Overlord during the Second World War. On June 6, 1944, the Allies invaded German-occupied France with the Normandy landings. "Omaha" refers to an 8-kilometer (5 mi) section of the coast of Normandy, France, facing the English Channel, from east of Sainte-Honorine-des-Pertes to west of Vierville-sur-Mer on the right bank of the Douve River estuary. Landings here were necessary to link the British landings to the east at Gold with the American landing to the west at Utah, thus providing a continuous lodgement on the Normandy coast of the Bay of the Seine. Taking Omaha was to be the responsibility of United States Army troops, with sea transport, mine sweeping, and a naval bombardment force provided predominantly by the United States Navy and Coast Guard, with contributions from the British, Canadian and Free French navies.

A naval mine is a self-contained explosive device placed in water to damage or destroy surface ships or submarines. Unlike depth charges, mines are deposited and left to wait until they are triggered by the approach of, or contact with, any vessel or a particular vessel type, akin to anti-infantry vs. anti-vehicle mines. Naval mines can be used offensively, to hamper enemy shipping movements or lock vessels into a harbour; or defensively, to protect friendly vessels and create "safe" zones. Mines allow the minelaying force commander to concentrate warships or defensive assets in mine-free areas giving the adversary three choices: undertake an expensive and time-consuming minesweeping effort, accept the casualties of challenging the minefield, or use the unmined waters where the greatest concentration of enemy firepower will be encountered.

A modern torpedo is an underwater ranged weapon launched above or below the water surface, self-propelled towards a target, and with an explosive warhead designed to detonate either on contact with or in proximity to the target. Historically, such a device was called an automotive, automobile, locomotive, or fish torpedo; colloquially a fish. The term torpedo originally applied to a variety of devices, most of which would today be called mines. From about 1900, torpedo has been used strictly to designate a self-propelled underwater explosive device.

U-boats were naval submarines operated by Germany, particularly in the First and Second World Wars. Although at times they were efficient fleet weapons against enemy naval warships, they were most effectively used in an economic-warfare role and enforcing a naval blockade against enemy shipping. The primary targets of the U-boat campaigns in both wars were the merchant convoys bringing supplies from Canada and other parts of the British Empire, and from the United States, to the United Kingdom and to the Soviet Union and the Allied territories in the Mediterranean. German submarines also targeted Brazilian merchant ships during both World Wars and, twice over, precipitated Brazil's decision to give up its neutral stance and declare war on Germany.

The French Fourth Republic was the republican government of France from 27 October 1946 to 4 October 1958, governed by the fourth republican constitution. It was in many ways a revival of the Third Republic that was in place from 1870 during the Franco-Prussian War to 1940 during World War II, and suffered many of the same problems. France adopted the constitution of the Fourth Republic on 13 October 1946.