A covered bowl of parrot eggs could tell a Yoruba king to abdicate
Yoruba monarchs ruled only while their people approved. If a king turned tyrannical or incompetent, the order to leave the throne might arrive as a symbolic message: parrot eggs in a covered calabash, delivered in Oyo by the head of the lawmakers. Bound by oath, the king was usually expected to take his own life.
Balance of power differed from state to state. Oyo had strong, near-absolute kings, while elsewhere councils of chiefs held real authority and the Oba, a priestly monarch, served more as a figurehead. Beneath the kingdoms ran a layered system that started at home, with the extended family under its own head, families forming towns under chiefs, and towns forming clans under an Oba who might answer to a higher Oba. Any adult was held to have roughly as much authority over a child as the parents.
Almost every Yoruba settlement traces its founding to princes of Ile-Ife, the spiritual homeland, and to the legendary ancestor Oduduwa. Sixteen established kingdoms claim descent from him. Ife enjoyed a golden age of art and ideas between 1100 and 1400 before Oyo overtook it as the dominant military power. Linguistic clues suggest the east was settled first, since western dialects show more innovations. In the nineteenth century, forces of the Sokoto Caliphate pushing south overran Ilorin and sacked Oyo's capital, and further advances were halted under the leadership of Ibadan and the Ijebu kingdom.
The land itself covers about 142,114 square kilometres across Nigeria, Benin and Togo, home to an estimated 55 million people. Mangroves and lagoons line the coast, rising inland to a plateau studded with waterfalls and inselbergs; the Idanre Hills top 1,050 metres, the highest point in western Nigeria. The south is dense hardwood forest of iroko and mahogany, soaked by rains that peak twice a year, and it anchors Nigeria's cocoa, rubber and oil palm output. The north shifts to wooded savanna with a single rainy season.
In the dry months, dusty harmattan winds blow down from the Sahara, occasionally reaching as far as Lagos.
Source: Yorubaland