The official numbering of the prime ministers starts with the first president of the Council of Ministers of the constitutional monarchy. A second column is added after the establishment of the Republic, numbering the prime ministers from there to the present day. Another column is added for the numbering inside the three regimes: First Republic, the Second Republic and Third Republic, with a fourth column in the "Second Republic" to mark the numbering of prime ministers since the 1926 revolution that established the "National Dictatorship" and since the replacement of the National Dictatorship with the Salazarist "Estado Novo". In the Third Republic, a fourth column is also used to distinguish the prime ministers of the provisional governments that existed during the period immediately following the Carnation Revolution of 1974 from the prime ministers that assumed office after the entry into force of Portugal's current democratic Constitution adopted 1976.