1340
Battle of Sluys sinks the French fleet
Edward III's archers, packed onto galleys, raked the moored French and Genoese ships off the Flemish coast in a savage boarding action. By evening seventeen thousand French sailors were dead and the Channel belonged to England for a generation. The first great battle of the Hundred Years' War was an English naval massacre that secured the sea lanes for invasion.
Ibn al-Shatir builds Damascus astronomical clock
The Damascene astronomer and timekeeper of the Umayyad Mosque constructed a sophisticated mechanical astrolabe and developed planetary models that eliminated the Ptolemaic equant, producing geometrically elegant alternatives that better predicted celestial positions. Copernicus's later lunar model is nearly identical to Ibn al-Shatir's, raising persistent questions about the transmission of Arabic astronomical theory to Renaissance Europe through Byzantium or Spain.
Battle of Salado: Castile and Portugal halt Marinid invasion
An Iberian Christian coalition crushed the last great African Muslim incursion across the Strait of Gibraltar. Castilian, Portuguese, and Aragonese knights smashed the army of Abu al-Hasan of Morocco on the Salado river in a decisive cavalry engagement. The Reconquista's southward grind would resume without further interruption from the Maghreb, and North Africa ceased to threaten Iberia militarily.
Oxford translation of the Mertonian Mean Speed Theorem
Mathematicians at Merton College, including Bradwardine and Heytesbury, derived a kinematic theorem describing uniformly accelerated motion: a body's distance equals what it would cover at its average speed. The proof used geometric reasoning that was startlingly modern in its precision. Galileo would rediscover the same proof three centuries later. Late medieval Oxford was quietly inventing physics.