Hundred Years' War: Battle of Sluys: The French fleet is almost completely destroyed by the English fleet commanded personally by King Edward III.

The Hundred Years' War was a conflict between the kingdoms of England and France and a civil war in France during the Late Middle Ages. It emerged from feudal disputes over the Duchy of Aquitaine and was triggered by a claim to the French throne made by Edward III of England. The war grew into a broader military, economic, and political struggle involving factions from across Western Europe, fuelled by emerging nationalism on both sides. The periodisation of the war typically charts it as taking place over 116 years. However, it was an intermittent conflict which was frequently interrupted by external factors, such as the Black Death, and several years of truces.

The Battle of Sluys, also called the Battle of l'Écluse, was a naval battle fought on 24 June 1340 between England and France. It took place in the roadstead of the port of Sluys, on a since silted-up inlet between Zeeland and West Flanders. The English fleet of 120–150 ships was led by Edward III of England and the 230-strong French fleet by the Breton knight Hugues Quiéret, Admiral of France, and Nicolas Béhuchet, Constable of France. The battle was one of the opening engagements of the Hundred Years' War.

Edward III, also known as Edward of Windsor before his accession, was King of England from January 1327 until his death in 1377. He is noted for his military success and for restoring royal authority after the disastrous and unorthodox reign of his father, Edward II. Edward III transformed the Kingdom of England into one of the most formidable military powers in Europe. His fifty-year reign is one of the longest in English history, and saw vital developments in legislation and government, in particular the evolution of the English Parliament, as well as the ravages of the Black Death. He outlived his eldest son, Edward the Black Prince, and was succeeded by his grandson, Richard II.