The arrival of Europeans to New Zealand, starting in 1642 with Abel Tasman, brought enormous changes to the Māori, who were introduced to Western food, technology, weapons and culture by European settlers, especially from Britain. In 1840 the British Crown and many Māori chiefs signed the Treaty of Waitangi, allowing New Zealand to become part of the British Empire and granting Māori the status of British subjects. Initial relations between Māori and Europeans (whom the Māori called "Pākehā") were largely amicable. However, rising tensions over disputed land sales led to conflict in the 1860s and large-scale land confiscations. Social upheaval and epidemics of introduced disease also took a devastating toll on the Māori people, causing their population to decline and their standing in New Zealand to diminish.