Immediately after the Act of Abjuration, Spain sent a new army to recapture the United Provinces. Over the following years, the Duke of Parma reconquered the major part of Flanders and Brabant, as well as large parts of the northeastern provinces. The Roman Catholic religion was restored in much of this area. In 1585, Antwerp — the largest city in the Low Countries at the time — fell to the Spanish, prompting over half its population to flee to the north. Between 1560 and 1590, the population of Antwerp plummeted from c. 100,000 inhabitants to c. 42,000.