The assassination of João Maria Ferreira do Amaral, the governor of Portuguese Macau, occurred on August 22, 1849, amid escalating tensions between local Chinese residents and Portuguese authorities. The growing dissatisfaction stemmed from restrictive policies imposed by colonial rule that limited local commerce and autonomy. As dissatisfaction boiled over, a group of Chinese locals targeted Amaral for assassination, igniting a cycle of violence and retribution. The assassination was not just a singular incident but rather a manifestation of the broader discontent among the local populace towards colonial governance and exploitation.

In retaliation for the assassination, the Portuguese government mobilized military forces, leading to the Battle of Passaleão three days later. This military confrontation occurred in the vicinity of Macau and involved significant Portuguese military presence. The Portuguese sought to assert their authority and retaliate against perceived attacks on their governance. The battle saw the use of artillery and infantry tactics by the Portuguese forces, resulting in a conflict that further strained relations between the local Chinese population and the colonial power.

The aftermath of the incident fostered lingering resentment and did little to resolve existing tensions. It also served to illustrate the complexities of colonial rule in Macau during the 19th century, where multiple interests coalesced around trade, sovereignty, and local control. The Portuguese authorities learned that their governance strategies needed to be reassessed in the face of local resistance and that failure to address local grievances could have dire consequences. Ultimately, this incident set the stage for ongoing conflicts and struggles over authority and autonomy that would define the region in subsequent years.