The Chilean Congress leads a revolt against Balmaceda in 1891, complaining about the heavy-handed rule of the president, and in particular his interference in congressional elections,.

Conservatives generally support the rebels; Liberals and Democrats back the president.

Along with some renegade Liberals, the newly emergent Radical Party aligns with the so-called congressionalists, not wishing to see legislative prerogatives curtailed just as the party is gaining clients and strength.

Those provincials resentful of the growing centralization of political and economic power in and around Santiago also back the rebellion, especially in the north.

Initially, the navy, the armed service that includes the highest percentage of aristocrats, sides with the rebels; the army sides with the president.