The relations between the Swedes and the Dutch shifted from uneasy coexistence to outright rivalry when both nations decided to focus on the Schuylkill River and built fortifications there in proximity to each other. Presumably the building materials consisted of the “large quantities of pine logs,” which had been lying in the Schuylkill throughout the winter. A similar building method had been used for Fort Nya Gothenborgh (see above). In April 1648 Hudde was informed by Native American sachems that the Swedes had already built several buildings on the Schuylkill. As they invited him to do likewise, he quickly contacted Stuyvesant in New Amsterdam. After obtaining permission Hudde proceeded to build a Dutch fortification, called Fort Beversreede, next to the Swedish Fort Nya Korsholm that had been built in 1647. An exchange of protests with the Swedish commander lieutenant Måns Nilsson Kling ensued, but nevertheless Hudde pushed on with the work. He surrounded the house with palisades (palisaden) against Swedish attempts to destroy it, as they had done with a previous West India Company house downstream. Hudde adds: “I have erected a fort so that he might not also come here to do the same.” Later in 1648 the Swedes “built a house in front of Fort Beversreede, whereby the entrance to this fort was virtually closed off.” Later that autumn, one of the Swedes at night “to deride us pulled the palisades of Fort Beversreede apart and broke through them,” which suggests that the fortification was not as sturdy as Hudde would have liked. Fort Beversreede was abandoned when the Dutch built Fort Casimir. Johnson assumes that Fort Nya Korsholm was also abandoned in 1651, at the same time as Fort Nya Elfsborg. As the concentration of Swedish forces was a likely reaction to the building of Fort Casimir by the Dutch, Johnson’s suggestion seems quite plausible. Native Americans burned down the abandoned Fort Nya Korsholm a few years later.