From 1872 to 1889, Yohannes IV was the Emperor of Ethiopia. And he was the first Ethiopian ruler to oppose slavery and he outlawed the pracfive of it in his empire. Anybody caught buying or selling salves were punished to death without mercy. He combatted the smallpox with introducing standard vaccinations and medical clinics were established in Adwa and Gondar in 1886. Yohannes IV was in power for 17 years. He defended his empire against Egypt, Italy and the Mahdists of the Sudan.
IG: Firstknowthyself