Short answers, pulled from the story.
Researchers uncovered evidence at the Kenyan site of Olorgesailie in 2018 dating to about 320,000 years ago. This discovery revealed early modern behaviors including long-distance trade networks involving goods like obsidian and the use of pigments.
The Kingdom of Aksum existed from approximately 100 to 940 CE centered on Eritrea and northern Ethiopia. It grew from the proto-Aksumite Iron Age period to achieve prominence by the 1st century CE under rulers such as Zoskales who governed the port of Adulis.
Vasco da Gama visited Mombasa in 1498 marking the beginning of Portuguese exploration in current-day Kenya Tanzania and Mozambique. Portugal established a strong presence in southern Mozambique since the 15th century expanding up to Mombasa in present-day Kenya.
South Sudan peacefully seceded from Sudan in 2011 six and a half years after a peace agreement ended the Second Sudanese Civil War. The region endured conflicts including the Ethiopian Civil War from 1974 to 1991 and the Rwandan genocide against the Tutsi which occurred in 1993.
Global plate tectonic forces created the East African Rift separating both the Somali Plate and Nubian Plate at 7mm per annum. This geological activity formed Mount Kilimanjaro and Mount Kenya which stand as the two tallest peaks in Africa.
Eastern Africa had an estimated population of 260 million in 2000 projected to reach 890 million by 2050 with average growth rate of 2.5% per annum. UN estimates suggest this figure will quintuple over the course of the 21st century to 1.6 billion as of 2100.