century it was engaged in political expansion and consolidation in the region. Under Oba (king) Ewuare (), the state was organised for conquest. He solidified central authority and initiated 30 years of war with his neighbours. At the time of his death, the Benin Empire extended to Dahomey in the West, to the Niger Delta in the East, along the West African coast, and to the Yoruba towns in the north. The oba ruled with advice from the uzama, a council consisting of chiefs of powerful families and town chiefs of different guilds. Later its authority was diminished by the establishment of administrative dignitaries. In particular, Ewuare's grandson Oba Esigie (1504–1550) eroded the power of the uzama and increased contact and trade with Europeans, especially with the Portuguese who provided a new source of copper for court art. After the 16th century, Benin mainly exported pepper, ivory, gum, and cotton cloth to the Portuguese and Dutch, who resold it to other African societies along the coast. Women wielded political power in the empire. For example, the queen-mother who produced a future oba wielded immense political influence. Benin was never a significant exporter of slaves, as Alan Ryder's book Benin and the Europeans showed. By the early 1700s, the empire was wrecked with dynastic disputes and civil wars. However, it regained much of its former power in the reigns of Oba Eresoyen and Oba Akengbuda. In 1897, the British sacked Benin City. Sungbo's Eredo and the walls of Benin were built amid 1st millennium CE, prior to 10th century CE. Niger Delta and Igbo The Niger Delta comprised numerous city-states with numerous forms of government, comparable to those of the Swahili people in East Africa. These city-states were protected by the waterways and thick vegetation of the delta. Some, like Bonny, Kalabari, and Warri, had kings. Others, like Brass, were republics with small senates, and those at Cross River and Old Calabar were ruled by merchants of the ekpe society. The ekpe society regulated trade and made rules for members known as house systems. Some of these houses, like the Pepples of Bonny, were well known in the Americas and Europe. The region was transformed by trade in the 17th century CE. The Igbo primarily lived east of the delta, with the exception of the Anioma on the west side of the delta. The Igbo Kingdom of Nri rose in the