European exploration of Africa
One of the ships under command of Diogo Dias arrived at a coast that was not in East Africa. Two years later, a chart already showed an elongated island east of Africa that bore the name Madagascar. But only a century later, between 1613 and 1619, did the Portuguese explore the island in detail. They signed treaties with local chieftains and sent the first missionaries, who found it impossible to make locals believe in Hell, and were eventually expelled.
Ambohimanga
Madagascar's central highlands, including the area around Ambohimanga, were first inhabited between 200 BCE–300 CE by the island's earliest settlers, the Vazimba, who appear to have arrived by pirogue from southeastern Borneo to establish simple villages in the island's dense forests. By the 15th century the Merina ethnic group from the southeastern coast had gradually migrated into the central highlands where they established hilltop villages interspersed among the existing Vazimba settlements, which were ruled by local kings. The tombs of at least four Vazimba are located on or around Ambohimanga hill and are sites of pilgrimage, including the tombs of Ingorikelisahiloza, Andriantsidonina, Ramomba and Kotosarotra. In the mid-16th century the disparate Merina principalities were united as the Kingdom of Imerina under the rule of King Andriamanelo (1540–1575), who initiated military campaigns to expel or assimilate the Vazimba population. Conflict with the Vazimba led Andriamanelo to fortify his hill town using earthen walls, stone gateways and deep defensive trenches. This fortified town model, called a "rova", was propagated by the noble class throughout Imerina until French colonization of Madagascar in 1895.