made war on others to capture slaves for this purpose. Oyo was known to punish disobedience by wholesale slaughter of the erring community, as it accomplished in Allada in 1698. Political structure The Oyo Empire developed a highly sophisticated political structure to govern its territorial domains. Scholars have not determined how much of this structure existed prior to the Nupe invasion. After reemerging from exile in the early 17th century, Oyo took on a noticeably more militant character. The influence of an aggressive Yoruba culture is exemplified in the standards placed on the oba (king) and the roles of his council. The Alaafin of Oyo The oba (meaning 'king' in the Yoruba language) at Oyo, who was referred to as the Alaafin of Oyo (Alaafin means 'owner of the palace' in Yoruba), was the head of the empire and supreme overlord of the people. He was responsible for keeping tributaries safe from attack, settling internal quarrels between sub-rulers, and mediating between those sub-rulers and their people. The Alaafin of Oyo was also expected to give his subordinates honours and presents. In return, all sub-rulers had to pay homage to the Oba and renew their allegiance at annual ceremonies. The most important of these was the Bere festival, marking the acclamation of successful rule by the Alaafin. After the Bere festival, peace in Yorubaland was supposed to last for three years. The king could not be disposed of but could be compelled to commit suicide if he was no longer wanted. This was done by sending Bashorun (The prime minister) to present either an empty calabash or a dish of parrot's eggs to him and pass a sentence of rejection, known as Awon Eniyan Koo (i.e. the people reject you, the world rejects you and the gods reject you also). According to tradition, the Alaafin was expected to commit ritual suicide thereafter. Selection of the Alaafin The Oyo Empire was not a purely hereditary monarchy, nor was it an absolute one. The Oyo Mesi selected the Alaafin. He was not always closely related to his predecessor, although he did have to be descended from Oranmiyan, a son of Oduduwa, and to hail from the Ona Isokun ward (which is one of the three royal wards). At the beginning of the Oyo Empire, the Alaafin's eldest son usually succeeded his father upon the throne. This sometimes led the crown prince, known as