In the years after the Battle of Gembloux—one of the decisive engagements of the Eighty Years’ War between the rising Habsburg Empire and the Low Countries—the Spanish governor-general, Alessandro Farnese, slowly consolidated his control of Flanders and Brabant. Spanish control of the southern Netherlands was complete in August 1585 when Farnese finally captured Antwerp, in what is now Belgium, after one of the most technically brilliant actions of the conflict.
Antwerp was the richest and most populous city in the Netherlands and a Calvinist rebel stronghold ever since Spanish soldiers sacked it in 1576, after which most of the Low Countries rose up in rebellion against the Habsburgs. In July 1584, Farnese laid siege to Antwerp. He constructed a network of forts that cut off access to Antwerp by land. Next, he decided to block the Scheldt River, which connected Antwerp to the rebel-controlled north. Huge piers were thrown out from heavily armed forts on either side of the Scheldt. Between them, a floating bridge of connected barges armed with cannon was constructed. The massive structure was completed on February 25, 1585.
Meanwhile the Dutch rebels had cut the dykes around Antwerp, hoping to flood the region, allowing their ships to bypass the blockade. Farnese still controlled the last dyke before Antwerp, the Kouwenstein, so his bridge was not outflanked. On the night of April 4, an attempt was made to destroy the bridge by floating explosive ships down the Scheldt from Antwerp. The plan caused considerable damage, but Farnese’s engineers were able to repair the bridge. A similar attempt on May 20 failed. Elsewhere, rebels from the north failed twice to capture the Kouwenstein on May 6 and 26 . On August 17, after a siege that lasted fourteen months but caused no damage to the city itself, Antwerp surrendered.
After taking control of Antwerp, Farnese decreed that all its Protestants must convert to Catholicism or be exiled. Consequently, just under half of Antwerp’s population of about 80,000 migrated north, while the Spanish assault ground to a halt just north of the city. The ensuing frontier between the majority Catholic and Protestant populations effectively divided what are now Netherlands and Belgium today, their borders codified under the terms of the Treaty of Westphalia in 1648.
Losses: Spanish, at least 1,600 of 11,700; Dutch rebels, several thousand of 20,000.