Al-Farghani's Mistake

While expanding the urban settlements along the Tigris, the 9th century Abbasid caliph al-Mutawakkil needed a canal to bring water to a new city, al-Jaʻfariyya (after the caliph's birth name). He gave two courtiers the job of finding an engineer to design and build the canal. Two brothers, Muhammad and Ahmad ibn Musa, went for the expertise of al-Farghani (c.800 - 870).

al-Farghani was one of the most famous astronomers in the Muslim world in the 9th century. He had written a summary of Ptolemy's Almagest called Elements of astronomy on the celestial motions with more accurate data. Columbus used al-Farghani's calculations on his voyages across the Atlantic. Under a previous Abbasid caliph, al-Ma'mun, al-Farghani and a team had used the curvature between two points to calculate the diameter of the Earth.

He had also worked as an engineer, and for al-Mutawakkil had successfully created the New Nilometer in Old Cairo (more on that later). So designing a canal was not outside of his abilities. There was something wrong with the construction, however. A miscalculation made the entrance to the canal too deep. Water entering it would have to be abnormally high to be able to enter the rest and flow to its destination.

al-Mutawakkil was angered, and sent someone to figure out how culpable the two brothers were for the error. The investigator was not keen to see Muhammad and Ahmad punished, so he kept delaying his report. In fact, he delayed it long enough that it became a non-issue after the assassination of al-Mutawakkil, saving the lives of the brothers.

al-Farghani was not known for making mistakes, and tomorrow we'll look at some of his accomplishments, as well as explain the New Nilometer, which is exactly what you think it might be based on the name. See you then.

Great Mosque of Samarra

During the reign of the Abbasid caliph al-Mutawakkil (822 - 861), he commissioned several building projects. Up to 20 palaces are listed as his work, their cost totaling between 258 and 294 million dirhams.

One of his projects was a huge mosque in Samarra along the Tigris River. His desire for ostentatious displays of wealth and devotion made it the largest mosque in the world at the time, and it was completed in only three years.

The minaret (shown here) is 171 feet high and 108 feet wide, the top reached by a spiral ramp. It is all that remains of the original structure. The main building was constructed from baked brick octagon piers with four columns in the corners of imported marble. It had 17 aisles, and the walls were covered with dark blue tiles.

A total of 16 doors allowed the faithful inside, where light was provided by 28 windows, 24 of were oriented by the qibla, the direction to face when praying. A fountain in the center was believed to be carved from a single stone and delivered by elephants. That had been commissioned by al-Mutawakkil's predecessor, his brother al-Wathiq. The baked brick ceiling was 35 feet high, supported by 464 pillars.

In 1278, the mosque (but not the minaret or outer wall) was destroyed when Iraq was invaded by Hulagu Khan's Mongols. A restoration process started in 1956.

The construction of the Great Mosque was part of a plan to make Samarra the center of an expansive urban area, so there were other projects in the area. Part of this expanded area was named al-Mutawakkiliyya for himself. Another new city he founded needed water, and he commanded two courtiers, the brothers Muhammad and Ahmad ibn Musa, to make it happen. They ignored local engineers and turned instead to al-Farghani, an astronomer. He was very smart, and a good mathematician with a good reputation, but he made a tiny mistake with great consequences. That's a story for tomorrow.

Ending Religious Tolerance

The 10th Abbasid caliph was not intended to rise to that position. Ja'far ibn Muhammad ibn Harun was born in 822 to an Abbasid prince and a slave concubine. His father, al-Mu'tasim, was a court official to Ja'far's uncle, his father's brother caliph al-Ma'mun. Both al-Ma'mun and al-Mu'tasim were sons of Harun al-Rashid, who reigned at the start of Islam's Golden Age.

When al-Ma'mun died in 833, he nominated his brother rather than his son to rule. When al-Mu'tasim died, his eldest son (Ja'far's brother al-Wathiq) became caliph. al-Wathiq had a fairly non-dramatic reign except for ongoing battles with the Byzantine Empire. al-Wathiq ended that conflict for several years after agreeing to a prisoner exchange in 845. His death from natural causes in his mid-30s caught the nation by surprise. His son was fairly young, and so for the second time in that dynasty the succession went "sideways" to a brother rather than a son. Ja'far found himself elevated to the caliphate and taking the regnal name al-Mutawwakil ala Allah, "He who relies on God." He was 26 years old. (The illustration is of hid face on a silver dirham.)

His well-educated brother had been a lover of poetry and the arts, enjoying poets, scholars, and musicians. In contrast, al-Mutawwakil cared more for power and grandiosity. His reign was known for ending the religious tolerance of his predecessors. Whereas dhimmi ("protected ones"; a designation given to those of other faiths) had many privileges, he took steps to revoked or disrespect them. In 850 he decreed that all Jews and Christians had to wear garments that distinguished them from the faithful: honey-colored (yellow) hoods and belts. Moreover, their places of worship were destroyed and they were no longer allowed to hold public office.

An ancient sacred cypress of the Zoroastrians was ordered cut down to be used as timber for a new palace. It was 1400 years old, and legend said it had been brought by Zoroaster from heaven.

He even attacked fellow Muslims. There was on ongoing debate over whether the Koran was created or not. That is (to put it simply): was it produced by a man, or was it divine knowledge that was then "un-created" by a man, because it was eternal? There was a sect that rejected the idea that the Koran was the literal word of and co-=eternal with God, and therefore did not exist until Muhammad wrote it. al-Mutawwakil stomped on this heavily, taking hostile steps to anyone promoting the doctrine that the Koran was created by a man.

al-Mutawwakil had named his eldest son, al-Muntasir, as his successor, but over time was showing favor to his second son, al-Mu'tazz. The two sons had support from different political factions, and the elder was unhappy with his father's shifting attention, especially when the younger was given the privilege of leading prayers at the end of Ramadan. Other humiliations followed, and a faction approached the elder son with a plan to assassinate his father. al-Muntasir was not opposed. The plan was carried out in December 861, and al-Muntasir became caliph. al-Mutawwakil had died before lumber from the Zoroastrian cedar arrived to be used.

Unfortunately, this began a period known as the Anarchy at Samarra, lasting until 870 and almost destroying the Abbasid Caliphate.

Let's turn away from politics and find something good about al-Mutawwakil's reign. How about the Great Mosque of Samarra? I'll bet there are some interesting stories there. I'll check it out and get back to you tomorrow.