Deriving authority from the powerful Sejm, the prime minister and the council of ministers, in theory, faced few constitutional barriers from the presidency to pass and proceed with legislation. In reality, however, the premiership remained extraordinarily insecure due to the harsh political climate of the early Second Republic, marked by constant fluctuating coalitions within parliament. Fourteen governments and eleven prime ministers rose and fell between 1918 and 1926, with nine governments alone serving between the five-year March Constitution era. Deeply frustrated with the republic's chaotic "sejmocracy" parliamentary structure, Piłsudski led rebellious Polish Army units to overthrow the government in the May Coup of 1926, effectively ending the Second Republic's brief experiment with parliamentary democracy, as well as the prime minister's free and popular elected mandate for the next sixty years.