 As far as it is possible to tell, slavery seems to have increased in the early-19th century with increased numbers of prisoners being taken by Māori military leaders (such as Hongi Hika and Te Rauparaha) to satisfy the need for labor in the Musket Wars, to supply whalers and traders with food, flax and timber in return for western goods.The intertribal Musket Wars lasted from 1807 to 1843; northern tribes who had acquired muskets captured large numbers of slaves.About 20,000 Maori died in the wars, which were took place mainly in the North Island.