Roma live around the world, from the United States to Australia, but most reside in Europe. They are the largest ethnic minority in the European Union. They historically were nomadic, moving around by horse cart, a lifestyle that historians say began out of necessity. They were unable to own land or work at the professions of the white Christian class, so they worked as tradesmen or seasonal laborers. In some Western European countries, such as France and Britain, Roma communities still move by caravan, but most have settled. They make up significant minorities in several countries in Central and Eastern Europe, notably Romania and Bulgaria.