The years of the slave trade in the late nineteenth century created problems for Patteson and other missionaries. Numerous British ships, known as blackbirders, sailed to the islands to recruit, often by deception and force, labourers to work on plantations in Australia or Fiji, under extremely harsh conditions. Sometimes ship captains ordered crews to cut off the heads of resisters, selling the heads at other islands and entering into the headhunter cultures. The slave-trade was technically illegal in the South Pacific at that time, and the traders called the natives indentured workers. Laws for their protection and return to their home islands were rarely enforced; the men were severely treated and many died; thousands of others were abandoned in the work islands.