The Central African Republic (CAR) was third in 2016 on the Fragile State Index published by the Fund for Peace. The twelves indicators used are demographic pressure (too many people v resources), refugees/internally displaced people, group grievances, human flight/brain drain, uneven economic development, poverty/economic decline, state legitimacy (e.g. corruption), public service, human rights/rule of law, security apparatus/use of force, factionised elites, and external interventions.
The area was one of the earliest mixing point of the expanding Bantu, Nilo-Saharan and Afroasiatic speaking groups. The expansions were slow, with lots of space and a history of farming people settled, grew a little, pushed on a little, probably (we think) fought a little. 16/17th slave trading and colonialism sped things up. Kingdoms rose up off the back of trade, but you wouldn't have wanted to be close to enemies or you became the product. The 'civilising mission' that came with colonialism and the end of slavery didn't mean the end of forced labour (e.g. mandatory cotton cultivation and building of railways). The first of (or continuation of) several forceful take-overs followed 1960 independence. Despite an abundance of natural resources, CAR remains one of the poorest countries in the world.
Bouar Megaliths - date back to 2700-3500 BCE