The Nok civilization thrived between 1,500 BC and AD 200. It produced life-sized terracotta figures that are some of the earliest known sculptures in Africa[33][34][35][36][37] and smelted iron by about 550 BC and possibly a few centuries earlier.[29][30][31] Evidence of iron smelting has also been excavated at sites in the Nsukka region of southeast Nigeria: dating to 2000 BC at the site of Lejja[38] and to 750 BC at the site of Opi. Early history Main article: History of Nigeria before 1500 Royal Benin ivory mask, one of Nigeria's most recognized artifacts. Benin Empire, 16th century. The Kano Chronicle highlights an ancient history dating to around 999 AD of the Hausa Sahelian city-state of Kano, with other major Hausa cities (or Hausa Bakwai) of Daura, Hadeija, Kano, Katsina, Zazzau, Rano, and Gobir all having recorded histories dating back to the 10th century. With the spread of Islam from the 7th century AD, the area became known as Sudan or as Bilad Al Sudan (English: Land of the Blacks). Since the populations were partially affiliated with the Arab Muslim culture of North Africa, they began trans-Saharan trade and were referred to by the Arabic speakers as Al-Sudan (meaning "The Blacks") as they were considered an extended part of the Muslim world. There are early historical references by medieval Arab and Muslim historians and geographers which refer to the Kanem–Bornu Empire as the region's major centre for Islamic civilization.[citation needed] The Kingdom of Nri of the Igbo people consolidated in the 10th century and continued until it lost its sovereignty to the British in 1911.[39][40] Nri was ruled by the Eze Nri, and the city of Nri is considered to be the foundation of Igbo culture. Nri and Aguleri, where the Igbo creation myth originates, are in the territory of the Umeuri clan. Members of the clan trace their lineages back to the patriarchal king-figure Eri.[41] In West Africa, the oldest bronzes made using the lost wax process were from Igbo-Ukwu, a city under Nri influence.[39] The Yoruba kingdoms of Ife and Oyo in southwestern Nigeria became prominent in the 12th[42][43] and 14th[44] centuries, respectively. The oldest signs of human settlement at Ife's current site date back to the 9th century,[42] and its material culture includes terracotta and bronze figures. Pre-colonial era Further information: History of Nigeria (1500–1800) Depiction of Benin City by a Dutch illustrator in 1668. The wall-like structure in the centre probably represents the walls of Benin, housing the Benin bronze decorated historic Benin City Palace. In the 16th century, Portuguese explorers were the first Europeans to begin important, direct trade with the peoples of southern Nigeria, at the port they named Lagos (formerly Eko) and in Calabar along the region Slave Coast. Europeans traded goods with peoples at the coast; coastal trade with Europeans also marked the beginnings of the Atlantic slave trade.[45] The port of Calabar on the historical Bight of Biafra (now commonly referred to as the Bight of Bonny) became one of the largest slave-trading posts in West Africa in this era. Other major slaving ports were located in Badagry, Lagos on the Bight of Benin, and Bonny Island on the Bight of Biafra.[45][46] The majority of those taken to these ports were captured in raids and wars.[47] Usually, the captives were taken back to the conquerors' territory as forced labour; they were sometimes gradually acculturated and absorbed into the conquerors' society. Slave routes were established throughout Nigeria linking the hinterland areas with the major coastal ports. Some of the more prolific slave-trading kingdoms who participated in the Atlantic slave trade were linked with the Edo's Benin Empire in the south, Oyo Empire in the southwest, and the Aro Confederacy in the southeast.[45][46] Benin's power lasted between the 15th and 19th centuries.[48] Oyo, at its territorial zenith in the late 17th to early 18th centuries, extended its influence from western Nigeria to modern-day Togo. In the north, the incessant fighting amongst the Hausa city-states and the decline of the Bornu Empire allowed the Fulani people to gain headway into the region. Until this point, the Fulani, a nomadic ethnic group, primarily traversed the semi-desert Sahelian region north of Sudan with cattle and avoided trade and intermingling with the Sudanic peoples. At the beginning of the 19th century, Usman dan Fodio led a successful jihad against the Hausa Kingdoms, founding the centralised Sokoto Caliphate. This empire, with Arabic as its official language, grew rapidly under his rule and that of his descendants, who sent out invading armies in every direction. The vast landlocked empire connected the east with the western Sudan region and made inroads down south conquering parts of the Oyo Empire (modern-day Kwara), and advanced towards the Yoruba heartland of Ibadan, to reach the Atlantic Ocean. The territory controlled by the empire included much of modern-day northern and central Nigeria. The sultan sent out emirs to establish suzerainty over the conquered territories and promote Islamic civilization; the emirs in turn became increasingly rich and powerful through trade and slavery. By the 1890s, the largest slave population in the world, about two million, was concentrated in the territories of the Sokoto Caliphate. The use of slave labour was extensive, especially in agriculture.[49] By the time of its break-up in 1903 into various European colonies, the Sokoto Caliphate was one of the largest pre-colonial African states.[50] A changing legal imperative (the outlawing of the Atlantic slave trade in 1807) and economic imperative (a desire for political and social stability) led most European powers to support the widespread cultivation of agricultural products, such as the palm, for use in European industry. The slave trade continued after the ban, as illegal smugglers purchased slaves along the coast from native slavers. Britain's West Africa Squadron sought to intercept the smugglers at sea. The rescued slaves were taken to Freetown, a colony in West Africa originally established by Lieutenant John Clarkson for the resettlement of slaves freed by Britain in North America after the American Revolutionary War. British colonization Main articles: Colonial Nigeria and Royal Niger Company Britain intervened in the Lagos kingship power struggle by bombarding Lagos in 1851, deposing the slave-trade-friendly Oba Kosoko, helping to install the amenable Oba Akitoye and signing the Treaty between Great Britain and Lagos on 1 January 1852. Britain annexed Lagos as a crown colony in August 1861 with the Lagos Treaty of Cession. British missionaries expanded their operations and travelled further inland. In 1864, Samuel Ajayi Crowther became the first African bishop of the Anglican Church.[51] Flag of the Lagos Colony In 1885, British claims to a West African sphere of influence received recognition from other European nations at the Berlin Conference. The following year, it chartered the Royal Niger Company under the leadership of Sir George Taubman Goldie. By the late 19th and early 20th centuries, the company had vastly succeeded in subjugating the independent southern kingdoms along the Niger River, th