The capital of the last Abbasids.

Ancient Samarra
The remains of prehistoric Samarra were first excavated between 1911 and 1914 by the German Archaeologist Ernst Herzfeld. Samarra became the type site for the Samarra culture. Since 1946, the notebooks, letters, unpublished excavation reports and photographs have been in the Freer Gallery of Art in Washington, DC.

A city of Sur-marrati (refounded by Sennacherib in 690 BC according to a stele in the Walters Art Museum, Baltimore[citation needed]) is insecurely identified with a fortified Assyrian site of Assyrian at al-Huwaysh, on the Tigris opposite to modern Samarra.

The possibility of a larger population was offered by the opening of the Qatul al-Kisrawi, the northern extension of the Nahrawan Canal which drew water from the Tigris in the region of Samarra, attributed by Yaqut (Mu`jam see under “Qatul”) to the Sassanid king Khosrau I Anushirvan (531–578). To celebrate the completion of this project, a commemorative tower (modern Burj al-Qa’im) was built at the southern inlet south of Samarra, and a palace with a “paradise” or walled hunting park was constructed at the northern inlet (modern Nahr al-Rasasi) near to al-Daur. A supplementary canal, the Qatul Abi al-Jund, excavated by the Abbasid Caliph Harun al-Rashid, was commemorated by a planned city laid out in the form of a regular octagon (modern Husn al-Qadisiyya), called al-Mubarak and abandoned unfinished in 796.

Abbasid capital
In 221/836 the Abbasid Caliph Al-Mu’tasim founded a new capital at the banks of the Tigris. Here he built extensive palace complexes surrounded by garrison settlements for his guards, mostly drawn from Central Asia and Iran (most famously the Turks, as well as the Khurasani Ishtakhaniyya, Faraghina and Ushrusaniyya regiments) or North Africa (like the Maghariba). Although quite often called Mamluk slave soldiers, their status was quite elevated; some of their commanders bore Sogdian titles of nobility.

The city was further developed under Caliph al-Mutawakkil, who sponsored the construction of lavish palace complexes, such as al-Mutawakkiliyya, and the Great Mosque of Samarra with its famous spiral minaret or Malwiya, built in 847. For his son al-Mu’tazz he built the large palace Bulkuwara.

Samarra remained the residence of the caliph until 279/892, when al-Mu’tadid eventually returned to Baghdad. The city declined but maintained a mint until the early 10th century.

The Nestorian patriarch Sargis (860–72) moved the patriarchal seat of the Church of the East from Baghdad to Samarra, and one or two of his immediate successors may also have sat in Samarra so as to be close to the seat of power.

After the collapse of the Abbasid empire in about 940 Samarra was abandoned. Its population returned to Baghdad and the city rapidly declined. Its field of ruins is the only world metropolis of late antiquity which is available for serious archaeology.

Islamic significance
The city is also home to the al-Askari Mosque, containing the mausoleums of the Ali al-Hadi and Hasan al-Askari, the tenth and eleventh Shia Imams, respectively, as well as the place from where he went into occultation. Muhammad al-Mahdi, known as the “Hidden Imam”, is the twelfth and final Imam of the Twelvers. This has made it an important pilgrimage centre for the Twelvers. In addition, Hakimah and Narjis, female relatives of the Muhammad and the Imams, held in high esteem by Muslims, are buried there, making this mosque one of the most significant sites of worship.

The Sunnis also pray in the mosques similar to the Shi’a; they also conduct pilgrimages to these sites (coming as far as from South Asia), but they do not believe this to be obligatory, but rather an affair providing spiritual blessings.