The 16 May 1877 crisis (French: Crise du seize mai) was a constitutional crisis in the French Third Republic concerning the distribution of power between the President and the legislature. When the Royalist President Patrice MacMahon dismissed the Opportunist Republican Prime Minister Jules Simon, the parliament on 16 May 1877 refused to support the new government and was dissolved by the President. New elections brought in an overwhelming victory for the Republicans. Thus, the interpretation of the 1875 Constitution as a parliamentary system prevailed over a presidential system. The crisis ultimately sealed the defeat of the Royalist movement, and was instrumental in creating the conditions of the longevity of the Third Republic.