The Hispano-Portuguese War of 1876

The Hispano-Portuguese War of 1876 was a war fought between the Republic of Portugal and the Republic of Brazil against the Kingdom of Spain. The war began due to increased tensions and fear among the Spanish aristocracy that the spread of liberal ideas in Portugal would lead to a revolution in their own country, along with increased appeals from Pedro V to re-install the house of Braganza upon the throne of the country, promising to maintain a friendly foreign policy towards Spain in exchange for their help.

Background
In 1873, the Portuguese parliament abolished the monarchy due to the loss of Brazil the year prior.