The Netherlands is a constitutional monarchy governed under the constitution of 1815 as amended. The hereditary monarch is the head of state; the prime minister is the head of government. There is a bicameral legislature, the States General. Members of the deliberative upper house, the 75-seat First Chamber, are elected by the 12 provincial councils. Members of the more powerful lower house, the 150-seat Second Chamber, are popularly elected. All legislators serve four-year terms. The royal succession is settled on the house of Orange (see Nassau), which adheres to the Dutch Reformed Church. Administratively, the country is divided into 12 provinces.