The Aro Confederacy, whose powers extended across Eastern Nigeria and beyond, was challenged in the last decades of the 19th century by increasing British penetration of the hinterland. The Aro people and their allies resisted the penetration which threatened their culture, influence, and sovereignty. Reasons for the war advanced by Sir Ralph Moore, the British High Commissioner of the Nigerian Coast Protectorate, included: The Aro peoples use of divinatory practice in shrines dedicated to the god Ibin Ukpabi, to dominate enslavement activities, was perceived to be contrary to the imperial ambition of British powers, which was the cause of a need to consequently destroy the primary shrine, based at Arochukwu.
Aro Opposition
The Aros knew that British penetration would destroy their economic dominance of the hinterland. They also opposed their religion, Christianity, which threatened their religious influence through their oracle Ibini Ukpabi. The Aro led raids and invasions on communities were conducted in order to undermine British penetration since the 1890s. While the British prepared for the invasion of Arochukwu in November 1901, the Aro launched their last major offensive before the Aro Expedition by British forces. Aro forces led by Okoro Toti sacked Obegu which resulted in 400 people dying. This attack quickened British preparation for their offensive.
Aro Expedition
Sir Ralph Moore and the Royal Niger Company had planned the attack on the Aros and the Ibini Ukpabi oracle since September 1899 but due to lack of necessary manpower, it was delayed until November 1901. On November 28, Lt. Col. Arthur Forbes Montanaro led 87 officers, 1,550 soldiers and 2,100 carriers in four axes of advance to Arochukwu from Oguta, Akwete, Unwana and Itu on a counter-insurgency campaign. As expected, Aro forces resisted all axes strongly, although they lacked modern weapons. However, Arochukwu was captured on December 28 after four days of fierce battles in and around the city. As a result, the Ibini Ukpabi shrine was allegedly blown up. Battles between British and Aro forces continued throughout the region until spring 1902 when Aro forces were defeated in the last major battle at Bende. The Aro Expedition ended three weeks later.
Result of the war
Some of the Aro leaders, like Okoro Toti, were arrested, tried by tribunals, and hanged. The Aro Confederacy was destroyed and Eze Kanu Okoro, went into hiding but was later arrested. Although Aro dominance crumbled in March 1902, many Aros took part in later resistances against the British in the region such as in Afikpo, Ezza, and other areas where the Aro had a particularly significant presence. The defeat of the Aro did help the British to open up the interior, but serious opposition to British penetration in Igboland clearly did not end with the Anglo-Aro War. In the years that followed, the British had to deal with many other conflicts and wars in various parts of Igboland such as the Nri Conflict, Ekumeku War, Igbo Women's War, etc.
