In the early 17th century Australia was first discovered by the Dutch who explored parts of it, but did not try to colonize it. In 1770 it was rediscovered by the British explorer James Cook who reported to the British government that it seemed like a good place to establish a colony. But it was not until after the American Revolutions that the British government began to take an interest in Australia. Because of the over-crowded prisons at home, the British government had been sending convicts to the American colonies for quite some time. But with American independence, Britain now needed a new place to send them. So starting in 1787 Britain began to establish penal (prison) colonies in Australia (six in all). By 1850 all the people living in the colonies had been given their freedom, but the colonies were still controlled by Britain. In 1901 the six colonies became the independent commonwealth of Australia.