Aboriginal peoples lived in Australia for thousands of years before Europeans arrived. They suffered greatly as a result of the arrival of the British in Australia. When Captain Cook visited in the late 1700s it is estimated that there were about 750,000 Aborigines. By the 1920s this number had fallen by around 90%. There were violent clashes between the Aborigines and the settlers in the early years. However, most deaths were caused by diseases that Europeans brought to Australia, and the gradual takeover of Aboriginal lands for farms and settlements. British farming methods, like the use of wire fences, disrupted the traditional Australian way of life and led to further violence between British settlers and Aborigines. The introduction of sheep and rabbits devastated their environment, their food sources and hunting grounds. Settlers often killed Aborigines who trespassed onto 'their' land. Many Aborigines moved to the towns to try and make a living. Here they suffered discrimination and disease, with alcoholism being a particular problem. British governors and officials in Australia were generally less harsh towards the Aborigines than the settlers of British descent. After the British handed over direct rule to Australia in 1901, the treatment of Aboriginal peoples did not improve.