The Maori first settled in New Zealand between 800-1000 AD. Over subsequent centuries they developed their culture and expanded settlements. European contact began in 1642, and epidemics killed 60% of the southern North Island Maori population in 1790. Between 1825-1918, 20,000 Maori were killed in internecine warfare involving muskets. In the 19th century the idea of a Maori King was proposed, and resistance to colonization continued despite British sovereignty established via the Treaty of Waitangi in 1840. Traditional Maori education was orally based and focused on cultural transmission, while food sources included crops like kumara as well as hunting and fishing.