The islands were colonized by Berber groups from northwest Africa. The indigenous inhabitants were called guanches, although this label correctly applies only to Tenerife. After being conquered by the Spanish in the fifteenth century, the natives were assimilated quickly. The Canarians today are a homogeneous and well-defined ethnic group who stress their differences from the Spanish, whom they call peninsulares or, more pejoratively, godos. The islands were of major strategic importance during European expansion and their harbors were of value in the trading routes between Europe and America. Since 1852 the islands have had free ports that serve to increase the volume of commercial traffic. Although historic movements for independence have existed, the desire for political sovereignty generally takes the form of a desire for political autonomy. After the democratization of Spain in 1977, the Canary Islands received autonomous status in 1982. In recent times, conflicts over political and economic power in the archipelago have been continuous between Gran Canaria and Tenerife, the most important islands. All national political parties are represented throughout the Islands, although the local parties have strong support and demonstrate the strong insular identities that characterize Canarian society.