Hasan ibn Ali ibn Muhammad (c. 6 December 846 – 4 January 874) also known as Hasan al-Askari was the eleventh and the penultimate Imam of the Twelver Shia Muslims. His title al-Askari is derived from the Arabic word Asker for army. He was given this title because he lived in Samarra, a garrison town.[5] He was 22, when his father was killed. The period of his Imāmate was six years and he died at the age of 28 and was buried in Samarra.[6]