The Ethiopian Empire
The Ethiopian Empire is known as the last stronghold of Africa. It covered the northern half of modern-day Ethiopia beginning in 1137 with the Zagwe dynasty. The Zagwe dynasty continued the Christianity of the Aksum Empire that existed prior to the conquest of the region by Queen Yodit (whose successors were overthrown by Mara Takla Haymanot the founder of the Zagwe dynasty).
In 1270, the Zagwe dynasty was overthrown by a King who claimed to be of the same lineage of the Aksumite kings who were descended from Solomon. Thus, the Solomonic dynasty was founded by the Habesha, who gave Abyssinia its name. This dynasty lasted until the late 20th century and conquered and incorporated all the people within modern Ethiopia. The Empire also fought off the Italian, Arab, and Turkish armies in order to maintain independence for hundreds of years.
There were numerous monasteries built during the early period of the Ethiopian Empire which perpetuated the Christian culture. From 1200 to 1250, beautiful rock carved churches were created to show the religious mindset of the Ethiopian kingdom and its reconnected ties to Jerusalem. Economic revival came during the Zagwe dynasty, and trade with the Muslim world flourished. Gold, ivory, frankincense, and slaves were exported out of Ethiopia. However, Abyssinian law forbade that Christian slaves be exported to Muslim lands.
It was during the Solomonic dynasty that much of the expansion of the Empire occurred, and the export of slaves exploded. Thousands of slaves were sold to the Ottoman Empire, and the population drastically declined in the Lake Tana region. The expansion caused problems with other regions and many tried to conquer Ethiopia. None of them completely succeeded until Italy finally got the upper hand against the Ethiopians in 1935.