This large beaten brass finial once formed the ornamental top to the tomb (qubba) of Muhammad Ahmad bin Abd Allah (1845-85) which is located in Omdurman in Sudan. After proclaiming himself the Mahdi, the messianic redeemer of the Islamic faith, in 1881, he led a successful military campaign against the Sudanese government. When he died in 1885 he was buried in a large tomb in Omdurman which was then the country's capital. In 1898 the British defeated the Mahdist army and restored Khartoum as the Sudanese capital; during this period the Mahdi's tomb was destroyed. The tomb was rebuilt in 1947.

The finial is in the shape of a crescent and spear, part of the Mahdist flag. Of the five finials originally surmounting the tomb, it is the only one to survive today. 

It was presented to Princess Beatrice (Princess Henry of Battenberg) in 1904 when she visited Khartoum. By the mid-20th century it was on display in the National Army Museum, Sandhurst before being transferred to the Royal Engineers Museum in Chatham.