This dissertation seeks to study slavery through an analysis of the institution of slavery in history and then focuses on the Brazilian slavery system. The work explains that social hierarchy constitutes the key to understand slavery through history. Ever since biblical time, slavery was forged in a number of different cultures and societies with the same characteristic: social hierarchy as the element that legitimated the control of a few by others. The Brazilian case was not different but had significant particularities. In Brazil, parallel to social hierarchy, the amalgam of the three races permitted miscegenation to be inserted in the Brazilian social code, with strong ramifications even after emancipation. In Brazilian society, miscegenation served to dissolve, that is to say, to bring together social groups, maintaining original differences based on social level rather than on quality. Therefore, to best understand Brazilian race relations, the heritage and particularities of the institution in Brazil will be discussed in this dissertation.