The Flax Trader by Brad Bradley

The very start of this fact-based fast-paced adventure story tells you this tall, clever 15 year old John Harris (1807-1872) means trouble: turbulent by nature, delighting in argument and excitement, he poaches deer, escapes jail, flees England, has a passionate love affair and a flogging, and jumps ship. He oversees a convict gang in brutal New South Wales, experiences bush-fires and murderous exchanges with aborigines. Trading muskets for flax around coastal New Zealand, he gets involved in genocidal intertribal warfare, head preservation, kidnap, cannibalism and slavery; he makes war and peace, marries Maori nobility, avoids revenge and black magic, sets up whaling stations, quarrels with missionaries, takes slave-girl wives, fights fanatical religious rebels, takes a terrible revenge, and tormented by guilt, finds a unique solution.