Haiti invaded the Dominican Republic with the intent to unify the island of Hispaniola under Haitian rule. This military action was led by President Jean-Pierre Boyer, who aimed to expand Haitian territory following the Haitian Revolution and Haiti's independence from France. The Dominican Republic, which had only recently declared independence from Haiti in 1821, was seen by Boyer as a potential source of instability and a threat to the fragile Haitian state. Boyer's actions reflected his ambitions to solidify and expand Haitian sovereignty, just a few years after the Dominican population had exerted its independence from years of Haitian governance.

The invasion was marked by a significant military presence and a sense of urgency from Haiti's leadership. Boyer's forces crossed the border into the Dominican territory and began establishing control swiftly. The Dominican Republic at the time was characterized by internal divisions and instability, which made it difficult for the newly independent state to mount a strong defense against the experienced Haitian army. The Haitian forces not only intended to enforce their governance but also sought to integrate Dominican resources and population into their political project.

Despite the initial success of the Haitian army, the ensuing occupation led to a complex relationship between Haitians and Dominicans. While Boyer aimed at political assimilation, the Dominicans resisted this imposition, leading to long-standing animosities. The conflict created profound social and political consequences that would resonate for generations, shaping the identities and national policies of both nations for years to come.