name for the god of Thunder. Either way, the royal family was devoted to the Spirits of Thunder (Jakuta) and War (Ogun). Early period (13th century–1535) The founding of Oyo is regarded as 1300 CE (common era), but this is only estimated through backtracking the chronology. Oranmiyan, the first oba (king) of Oyo, was succeeded by Oba Ajaka, Alaafin of Oyo. Ajaka was deposed, because he lacked Yoruba military virtues and allowed his sub-chiefs too much independence. Leadership was then conferred upon Ajaka's brother, Shango, who was later deified as the deity of thunder and lightning. Ajaka was restored after Sango's death. Ajaka returned to the throne thoroughly more warlike. His successor, Kori, managed to conquer the rest of what later historians would refer to as metropolitan Oyo. Oyo Ile The heart of metropolitan Oyo was its capital at Oyo-Ile (also known as Oyo Katunga, Old Oyo or Oyo-Oro). The two most important structures in Oyo-Ile were the 'Afin,' or palace of the Oba, and his market. The palace was at the center of the city close to the Oba's market called 'Oja-Oba'. Around the capital was an enormous earthen wall for defense with 17 gates. The importance of the two large structures (the palace and the Oja Oba) signified the importance of the king in Oyo. The Nupe occupation Oyo had grown into a formidable inland power by the end of the 14th century. For over a century, the Yoruba state had expanded at the expense of its neighbors. During the reign of Onigbogi, Oyo suffered military defeats at the hands of the Nupe led by Tsoede. Sometime around 1535, the Nupe occupied Oyo and forced its ruling dynasty to take refuge in the kingdom of Borgu. The Nupe sacked the capital, destroying Oyo as a regional power until the early 17th century. Imperial period (1608–1800) The Yoruba of Oyo went through an interregnum of 80 years as an exiled dynasty after its defeat by the Nupe. They re-established Oyo to be more centralized and expansive than ever. The people created a government that established its power over a vast territory. During the 17th century, Oyo began a long stretch of growth, becoming a major empire. Oyo never encompassed all Yoruba people, but it was the most populous kingdom in Yoruba history. Reconquest and expansion The key to the Yoruba rebuilding of Oyo was a stronger military and a