Between 1911 and 1915, Haiti was politically unstable: a series of political assassinations and forced exiles resulted in six presidents holding office during this period.[3] Various revolutionary armies carried out the coups. Each was formed by cacos, or peasant militia from the mountains of the north, or who invaded along the porous Dominican border. They were enlisted by rival political factions under the promises of money, which would be paid after a successful revolution, and the opportunity to plunder.[citation needed]