The Roma are a nation without a state. They are present as a transnational minority in many countries of the world. Originally from India, the Roma came to Europe around 11th century after a long migration through central Asia (Fraser 1992). During this journey, they maintained their culture and remained socially and culturally, as well as genetically, isolated from the surrounding majority populations. Today they comprise a mosaic of many Romani groups that differentiate between each other in their socio-cultural characteristics, including the languages they use and the religion they practice (Kalaydjijeva et al. 2004).
In order to explain the genetic differences between many different Romani groups, which have been confirmed by the most recent molecular-genetic methods, it is of extreme importance to know the historical background that brought the Romani nation to Europe, as well as the social organization that kept them isolated from the surrounding nations throughout history.