Despite Portugal maintaining a policy of neutrality, it was under pressure from Britain, its ally, to support British military efforts in Africa.

This included allowing British forces to pass through Portuguese territory and, more importantly, strengthening the defenses along Mozambique's northern border.

In response, Portugal deemed it essential to reinforce the frontier, especially the area along the Rovuma River, which had very limited Portuguese administrative and military presence.

On August 18, 1914, Portugal dispatched its first expedition to Mozambique, consisting of approximately 1,477 men, primarily drawn from the 3rd Battalion of the 15th Infantry Regiment.

The post at Maziua, situated far from the main Portuguese stronghold of Porto Amélia, was one of the weakest, defended by a small garrison of a sergeant and half a dozen indigenous soldiers from the Niassa Company's police force.