The "Trinitarios" took advantage of a Haitian rebellion against the dictator Jean-Pierre Boyer. They rose up on January 27, 1843, ostensibly in support of the Haitian Charles Hérard who was challenging Boyer for the control of Haiti. However, the movement soon discarded its pretext of support for Hérard and now championed Dominican independence. After overthrowing Boyer, Hérard executed some Dominicans, and threw many others into prison; Duarte escaped. After subduing the Dominicans, Hérard, a mulatto, faced a rebellion by blacks in Port-au-Prince. Haiti had formed two regiments composed of Dominicans from the city of Santo Domingo; these were used by Hérard to suppress the uprising.