What turned out to be the permanent halt to Spanish advance in the Low Countries after 1585 was chiefly the result of the increasing consolidation and resilience of the Dutch rebel state based on the provinces of Holland, its rapidly growing economic strength, and not least the increasingly formidable ring of sophisticated fortifications which the new Dutch regime, following the assassination of William of Orange by a Catholic fanatic in 1584, constructed in order to seal off the infant rebel state from Spanish-held territory to the south and east. This massive defensive ring ran from Sluis on the Scheldt estuary, in the south, via the great rivers and the IJssel line to Coevorden, in Drenthe and then on the Delfzij on the Ems estuary.
The English began by taking control of the English Channel with a smashing naval victory off Sluis in the Netherlands and then freely attacked northern France. The first major encounter on land took place near the channel coast at Crécy-en-Ponthieu in 1346 and was a thorough victory for the English. The English subsequently undertook an exhaustive siege of Calais, which capitulated after two years.
In 1337, England and France went to war after English king Edward III issued a claim on the French throne. The war, which became known as the Hundred Years' War, lasted from 1337 to 1453. The Hundred Years War started with the English defeating a French fleet off the coast of the Netherlands, at the Battle of Sluis, and then landing in France itself. The first major land battle took place at Crecy-en-Ponthieu in 1346 - and was again won by the English, who then launched a two year long siege of Calais, which finally fell in 1348.
The fall of Brussels was deferred till March, and that of Mechlin (19th July, 1585) and of Antwerp (19th August, 1585), till Midsummer of the following year; but, the surrender of Ghent (10th March 1585) foreshadowed the fate of Flanders and Brabant. Ostend and Sluys, however, were still in the hands of the patriots, and with them the control of the whole Flemish coast. The command of the sea was destined to remain for centuries with the new republic.