Elsewhere, in Botswana, the kgosis (or chieftains) of the various tribes are constitutionally empowered to serve as advisors within the national legislature as members of the Ntlo ya Dikgosi. Meanwhile, in Nigeria, the various traditional polities that currently exist are politically defined by way of the ceding of definite authority from the provincial governments, which in turn receive their powers to do so from a series of chieftaincy laws that have been legislatively created. Beyond this, residual powers are also derived by the Nigerian traditional rulers from both pre-existing customary laws and the remnants of the indirect rule policy of the colonial era.