First I write about the Sioux life and their traditions and examine the changes that white settlers brought to their life. Then I deal with their main wars with white people in the second half of the nineteenth century. I have chosen this period, because then white people wanted to get more and more lands and Indians had to fight for their properties. We can see famous, very brave and desperate Sioux warriors in these battles, some of whom lost their enthusiasm as the time passed. In chapter three the Great Sioux War is treated. It was a very glorious part of the Sioux history, as they were victorious in most battles. In the last chapter I write about the life of those Sioux Indians, who fled to Canada after the Great War. At the end of my thesis I deal with Sitting Bull, who was the chief of the Sioux Indians in the second half of the nineteenth century, and he is one of the bestknown Indian chiefs.