Five monarchies do not fit into any of the above groups by virtue of geography or class of monarchy: the Kingdom of Tonga in Polynesia; the Kingdom of Eswatini and the Kingdom of Lesotho in Africa; the Vatican City State in Europe and the Sovereign Military Order of Malta. Of these, Lesotho and Tonga are constitutional monarchies, while Eswatini and the Vatican City are absolute monarchies. Eswatini is unique among these monarchies, often being considered a diarchy: the King, or Ngwenyama, rules alongside his mother, the Ndlovukati, as dual heads of state. This was originally intended to provide a check on political power. The Ngwenyama, however, is considered the administrative head of state, while the Ndlovukati is considered the spiritual and national head of state, a position which more or less has become symbolic in recent years. The Pope is the absolute monarch of the Vatican City State (a separate entity from the Holy See) by virtue of his position as head of the Roman Catholic Church and Bishop of Rome; he is an elected rather than a hereditary ruler and does not have to be a citizen of the territory prior to his election by the cardinals. The Order of Malta describes itself as a "sovereign subject" based on its unique history and unusual present circumstances, but its exact status in international law is subject of debate. Samoa, the position is described in Part III of the 1960 Samoan constitution. At the time the constitution was adopted, it was anticipated that future heads of state would be chosen from among the four Tama a 'Aiga "royal" paramount chiefs. However, this is not required by the constitution, so, for this reason, Samoa can be considered a republic rather than a constitutional monarchy.