The military chess match between the Dutch and the Swedish for control of the Delaware River and its fur trade came to a climax when Peter Stuyvesant became director-general of New Netherland in 1647. His predecessor, Willem Kieft, had kept relations with the Swedes friendly, recognizing that his real threat came from the English. Stuyvesant, however, knew that the English would find New Netherland all the more enticing if it was sliced into two parts thanks to the Swedish incursion, and he decided to take bold military steps. The Swedes had established a base at Fort Christina (present-day Wilmington, Delaware), which gave them a better presence on the river than the Dutch had at Fort Nassau. In 1651, therefore, Stuyvesant built a new stronghold, which ouflanked Fort Christina. He called it Fort Casimir; but it was to be shortlived under that name, for the Swedes soon captured it and renamed it Fort Trinity. Not to be outdone, Stuyvesant returned at the head of a large military force in 1655 and defeated the Swedish once and for all, bringing an end to New Sweden.