Bartholomeus de Momper's business suffered terribly as a result of the Sack of Antwerp. On 4 November 1576, mutinying Spanish tercios of the Army of Flanders began the sack of Antwerp, leading to three days of horror among the population of the city, which was the cultural, economic and financial center of the Low Countries. Some 7,000 lives and a great deal of property were lost. The savagery of the sack led the provinces of the Low Countries to unite against the Spanish crown. The devastation also caused Antwerp's decline as the leading city in the region and paved the way for Amsterdam's rise. This rampage of Spanish soldiers in Antwerp caused significant financial loss to Bartholomeus de Momper. All his art stalls were sacked and his residence was plundered. As the tenant of the Schilderij Pand which he leased from the city government, Bartholomeus de Momper petitioned for a waiver of the rental payments on the ground that he was unable to operate his business for a while. The city magistrate only agreed to grant a waiver of the rental payment for half a year and instructed de Momper to ensure that his sub-lessees would return to operate their business in the Schilderij Pand. Bartholomeus de Momper resumed trade at seven art stalls in January 1577. Not long after, a new threat arose in Antwerp when German soldiers started to plunder the city and broke into the exchange where they pillaged all they could lay their hands on. After the Fall of Antwerp in 1585 de Momper had difficulty finding tenants for the stalls in the Schilderij Pand, but not because the art trade was in decline. The reason was that art dealers were running their trade on a lower floor of the bourse where they could display their paintings without having to rent the more expensive stalls in the Schilderij Pand from de Momper.