Why do you think belgium, which is not a large military power, was able to gain control of a sizable portion of central africa

The Belgian Monarch claimed it as a buffer zone between German and British claims in Africa as a way to "Prevent fighting."

  It was the personal property of King Leopold II. The constitutional monarch of Belgium.

Explanation:

  The king seizes the territories by convincing the European and Asian countries in the Berlin Conference that he was involved in humanitarian and philanthropic work. The State operated as a corporate private state run by Leopold II. The reign earned infamy because of the atrocities perpetrated on the locals.

  By the year 1908, the Belgium Parliament established the replacement of the Congo Free State (the name given by Leopold II) and renamed it as the Belgium Congo. Belgium took a paternalist attitude towards the citizens and treat them as if they were children. But the Africans had no role in legislation.

  I hope this answer helps you.