The Ecuadorian–Colombian War, or War of the Cauca (Guerra del Cauca), occurs in 1863 between the United States of Colombia, (now Colombia and Panama), and the Republic of Ecuador.
Under the Spanish Empire, Colombia and Ecuador had been part of the Viceroyalty of New Granada, and upon independence from Spain, they had co-existed as part of Greater Colombia between 1819 and 1831.
Periodic border disputes, arising from the lack of clear borders under the Spanish, are combined with occasional attempts to recreate Greater Colombia to produce tensions.
In 1861, conservative Gabriel Garcia Moreno (1821–75) becomes president of Ecuador and soon attemptesto unify his country, which is sharply divided by class, regional, and language differences, by handing over much power to the Roman Catholic Church, which he considers to be the people's chief social tie to achieving a sense of nationalism.
That decision deeply polarizes Ecuadorian politics, as liberals generally view the Church as an obstacle to social and political progress
