The Aro Confederacy was a powerful trading and political network centred on the Arochukwu people in what is now southeastern Nigeria. The Aro wielded enormous influence across Igboland and beyond through their control of the Long Juju oracle (Ibini Ukpabi) at Arochukwu and their extensive trade networks, including involvement in the slave trade.
As British colonial authority expanded into the interior of southeastern Nigeria in the late 19th and early 20th centuries, conflict with the Aro became inevitable. The British launched the Anglo-Aro Expedition (also called the Aro Expedition) in late 1901. The campaign began in November 1901, with multiple columns of British-led forces converging on Arochukwu from different directions.
The British captured and destroyed the Long Juju shrine at Arochukwu in December 1901, and the military campaign concluded in March 1902 with the final defeat and subjugation of the Aro Confederacy. The correct answer is therefore 1902, the year the expedition ended and the confederacy was effectively defeated.
The year 1901 marks the start of the expedition, not its conclusion. The years 1899 and 1904 do not correspond to the Anglo-Aro campaign.
Exam tip: The Anglo-Aro Expedition spanned 1901-1902. When a question asks when the Aro Confederacy was "defeated," the answer is 1902, when the campaign was completed.