Why?? Money.<p>To colonise a country at the other side of the world for Empire, area control and raw resources would be prohibitively expensive, even for one of the superpowers of the time.<p>What was needed was slave labor. The British did not have slavery. So they needed the next best thing; lots of people who could be forced to work without pay and for just the cost of a little food.<p>The answer to their prayers was a continuous supply of convicts. The answer to obtaining a continuous supply was to make very minor infractions of the law punishable by transportation. Thus, stealing a loaf of bread gave the government 7 man-years of labour in Australia.