After Rafael Carrera returns from exile in 1849, the president of El Salvador, Doroteo Vasconcelos, grants asylum to the Guatemalan liberals, who have harassed the Guatemalan government in several different ways.

José Francisco Barrundia has established a liberal newspaper for that specific purpose.

Vasconcelos supports a rebel faction named "La Montaña" in eastern Guatemala, providing and distributing money and weapons.

By late 1850, Vasconcelos is getting impatient at the slow progress of the war with Guatemala and decides to plan an open attack.

Under this circumstance, the Salvadorean head of state starts a campaign against the conservative Guatemalan regime, inviting Honduras and Nicaragua to participate in the alliance; only the Honduran government led by Juan Lindo accepts.

In 1851 Guatemala defeated an Allied army from Honduras and El Salvador at the Battle of La Arada.