The Imāms ‘Alī al-Hādī ("an-Naqī") and Hassan al-‘Askarī lived under house arrest in the part of Samarra that had been Caliph al-Mu'tasim's military camp (‘Askaru l-Mu‘tasim). As a result, they are known as the ‘Askariyyain "Dwellers in the Camp". They died and were buried in their house on Abī Ahmad Street near the mosque built by Mu‘tasim.[5] A later tradition attributes their deaths to poison.
Nasir ad-Din Shah Qajar undertook the latest remodelling of the shrine in 1868, with the golden dome added in 1905. Covered in 72,000 gold pieces and surrounded by walls of light blue tiles, the dome was a dominant feature of the Samarra skyline. It was approximately 20 m (66 ft) in diameter by 68 m (223 ft) high.