Pieter Karstense van Nortstrant was born about 1605 on the island of Norstrand. Coupled with the name of his father, Carsten or Kersten, and the fact that his children were baptized in the Lutheran Church in Amsterdam, it would seem that a German, Frisian or Danish origin is probable. It is uncertain when Pieter Karstense came to Amsterdam, possibly as a child with his father, though no record of the latter has been found there. The sons of Pieter Pietersen Ostrander (son of Pieter Karstense van Nortstrant), were called Van Norstrande or Van Nostrande, while Van Ostrande was used in other baptisms and eventually adopted the surname Oostrander and then the spelling as it is today Ostrander.