The Benin Empire fell to the British force during the Benin punitive expedition of 1897 during his reign.
Captain Phillip and his party started a trade mission to Benin City in January 1897, when the Oba and his subjects were celebrating the annual Igue festival a period when outside visitors were not welcome. They were encouraged to postpone their visit for two months but they refused. The parties were massacred however, some of them managed to escape. This event is referred to generally as the Benin massacre.
February 1897 the British forces launched an attack on Benin City, it was finally capture after 8 days of fighting.
The kingdom was destroyed and looted of it many valuable artifacts, Ologbohere the alleged masterminded of the massacre of Captain Phillip and his party was trialed and hanged. Oba Ovoranmwen was dethrones, and deported to calabar where he lives and dead on the month of January 1914 after sixteen years of British captivity. Buried at old calabar by official of colonial authority in the absent of his Benin royal family.
The truth is that Oba Ovoranmwen has nothing to do with the massacre of Captain Phillip and his party. The fall of Benin Empire was an event the British colonial power has always hoped for, it gave them the opportunity to stretch their Empire into West Africa hinterland.