The Banu Musa

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Speaker 1: Welcome to Stuff You Missed in History Class, a production of iHeartRadio.

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Speaker 2: Hello, and welcome to the podcast. I'm tra c e V Wilson, and I'm Holly Frye. I talked in a recent behind the scenes edition of the show that I had started playing Assassin's Creed Mirage at this point. I have finished playing Assassin's Creed Mirage because it's not that long of a game, and it also did not take long at all playing that game for me to encounter something that I wanted to talk about on the podcast. That was the Badu Musa. These were brothers who lived in Baghdad during the Islamic Golden Age, and that's the setting for Assassin's Creed Mirage. I also kept triple and quadruple checking whether these guys had come up on the show before, because we've done some previous episodes on figures from the Islamic Golden Age. The Banu Musa also created a number of automata, and we've talked about automata in some other episodes. All my digging through old notes though, suggest that no, apparently we never have. And also, just to be super clear, this is not a sponsored episode. I just got inspired by a video game. So the Islamic Golden Age is a term that was coined in the nineteenth century to describe a period of artistic and intellectual flourishing in the Muslim world. So as with terms like the Middle Ages and the Renaissance, this is a construct that's just meant to help us conceptualize the past. The Islamic Golden Age is usually described as starting with the founding of the House of Wisdom in the eighth century and ending with the siege of Baghdad by Mongol forces in twelve fifty eight. This was a period of invention, creativity, and discovery, as well as of preserving the knowledge of earlier eras. This does not, to be clear, mean that it was always peaceful or stable, and we'll get into some of that later. So this period began not long after the Abbasid Kaliphate took control from the Umayad Caliphate in the year seven fifty. I feel like we have always said this either as caliphate, caliphate or kaliphate on the show. They take a more Arabic pronunciation in this video game, and so it's always like Halif. The halifit the second Abbasid Caliph al Mansour moved the capital from Damascus to Baghdad. Then the fifth Abbasid caliph Harun al Rashid, established the Bite al Hikma, or the House of Wisdom there. Initially, the House of Wisdom, which is also sometimes called the Academy of Science, mainly functioned as a library and a translation center.

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Speaker 1: Initially, most of the translation work done at the House of Wisdom was from Persian into Arabic because the Abbassied court drew a lot of influence from Persia. But the seventh Abbasid caliph, known as alma Mun the scope and roll of the House of Wisdom. It became an academy and intellectual center, and much of the translation work shifted to texts in Greek philosophy and mathematics, as well as works in other languages. While this was a Muslim dynasty, scholars of a range of faiths worked at the House of Wisdom, including Islam, Judaism, Christianity, Zoroastrianism, and Hinduism. A lot of ancient works that we still have today exist only because they were preserved and translated in the House of Wisdom, and this focus on translation was part of a whole movement one that collected and translated works from all across the known world into Arabic. This work happened not just at the House of Wisdom, but also in other cities in the Kliphate. The Banu Musa lived in the ninth century, and we don't know much about the details of their personal lives. Their father was Musa ibn Shakir, who was probably Persian. In air naming, Ibn means son of So. Musa was the son of Shakir, and Banu means sons of So. The Banu Musa were the sons of Musa, and when described as individuals, their names would end in ibn Musa or ibn Musa ibn Shakir. This makes Banu Musa Brothers, which shows up in articles from time to time, a little bit wonky. It's not exactly wrong, but it's kind of redundant. You're basically tacking English words onto words that already say the same thing in another language. It's like calling them the sons of Musa brothers. Sources describe Musa ibn Shakir as a bandit or a highwayman when he was a young man, but later he turned away from that life to become an astronomer and astrologer. He became friends.

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Speaker 2: With Abu Alabas Abdallah alma Ibn al Rashid. This was the son of Kleaf Harun al Rashid and half brother of Mohammad al Amin. Although al Mamun was older than Alamin, al ma Mun's mother was an enslaved concubine and Alamin's mother was one of al Rashid's legitimate wives who was descended from another caliph, so al Mamin descended from caliph's on both sides and born from a marriage, was chosen to be his father's successor as caliph, while al Mamun was given sovereignty over the Kaliphate's eastern provinces in Khorasan. Harun al Rashid informed his sons of these arrangements in Ato two while they were performing the Haj to Mecca. The timeline is a little bit fuzzy here, but it seems like Musa ibn Shakir became part of al ma Mun's court while he was governing Khorasan, and he was still in that role when Musa died. That left Musa Ibn Shakir's three sons, Muhammad, Ahmad and Ala San in alma Mun's care, they were sent to the House of Wisdom in Baghdad, where they were tutored by an astronomer and astrologer named Yayabin Abif Mansur. Caliph Harun al Rashid died in Ado nine and soon the relationship between Alamin and al Mamun started to deteriorate. These brothers had signed formal agreements during their pilgrimage to Mecca, and among other things, al Mamun had agreed not to rebel against his brother, and Alamine had agreed never to invade alma Mun's territory or aid rebels in rising up against him. There's also a third half brother who was involved in all of this, but was not a major part of it. There was other instability going on at the same time as all this, but basically, in spite of their earlier agreements, the two half brothers started trying to undermine one another and this escalated into war. This is known as the Abassid Civil War, also called the Fourth Civil War or Fourth FeTNA. Alamine and alma Mun were at war with each other from eight eleven to eight thirteen, with alma Mun ultimately besieging Baghdad and taking control as Caliph. Ala Mun was killed, although his brother had apparently wanted him captured. The war continued after this among multiple factions, but to return to the Baanu Musa. After Almamun became caliph, they continued their work at the House of Wisdom, including carrying out commissions for him and eventually becoming a major part in the scholarly work that was done there. We know very little about the details of the three brothers' lives, and multiple sources used in this episode describe it as impossible to write separate biographies of them. One of the running jokes in Assassin's Creed Mirage is that the main character cannot tell those three brothers apart. We don't know exact birth or death dates for any of them, but since Muhammad is usually listed first, it's assumed that he was the oldest. He died in eight seventy three, and based on what we know of his life, he was probably at least seventy years old. The brothers do seem to have each had a primary focus for their work, Muhammad in astronomy, al Hassan in geometry and mathematics, and Ahmad in mechanics. Engineering, and the sciences, so they formed an interdisciplinary team, and many of their works were credited to all three of them collectively. We mentioned earlier that when alma Mun was caliph, he expanded the role of the House of Wisdom. Alma Mun wanted to put an end to the ongoing sectarian rivalries and factionalism within the Caliphate, and his dedication to preserving and expanding knowledge was connected to that effort. He was not successful at putting an end to all the various splits and rivalries, but he did encourage the House of Wisdom to take on new translation projects, and he founded astronomical observatories and other centers of learning and study. The Banu Muso were a big part of the translation efforts at the House of Wisdom. They had been orphans without a lot of resources when they first arrived there, but they became wealthy through their works for the caliphs, and they used that wealth to employ a group of translators, reportedly spending five hundred dinars a month. They hired people to travel into Byzantine territory to are ancient Greek texts and bring them back to Baghdad, and they took some of those trips themselves. Muhammad is credited with recruiting renowned mathematician and translator Tabid iban Kura of Haran in northern Mesopotamia to work at the House of Wisdom on one of these trips. There are some ancient works that we only have today because of translations that the Banu Musa commissioned and paid for, including that of the first century Greek mathematician Hero of Alexandria. In addition to their translation projects, the Banu Musa produced work of their own, and they did this through the reigns of multiple califs. We will talk more about that after a sponsor break. One of the things Caleph al Mamun directed the Banu Musa to do was to calculate the circumference of the earth to check the work of ancient scholars. They did this by going to the desert of Alsan Djar in what's now in northern Iraq. They measured the highest point of the pole star in the sky in the ninth century that would have been Polaris in the northern hemisphere as it is today. They walked north until the star's highest point was one degree higher than it had been. They measured the distance that they traveled with ropes. Then they repeated the process going south. Using these measurements, they calculated that the circumference of the Earth was twenty four thousand miles or thirty eight thousand, six hundred kilometers. That is pretty close the measurement recognized the day is twenty four thousand, nine hundred one miles or forty thousand, seventy five kilometers. They also calculated the length of a year at three hundred and sixty five days and less than six hours. The brothers work in astronomy was built on the framework of Alexandrian astronomer and mathematician Ptolemy, who lived around the year one point fifty. In the Ptolemaic model, the Earth is at the center of the universe, and the Sun, Moon, planets, and stars move around the Earth in circular orbits. This doesn't line up with how these bodies move when observed from the Earth. Ptolemy's explanation for this was that the Sun, Moon, planets, and stars were each contained within an invisible sphere, and that they moved in spherical epicycles while orbiting the Earth. Some descriptions of the Ptolemaic model include another sphere beyond the one containing the stars, which is the prime mover that powers all the others. Sometimes this is called the ninth sphere. This idea might not have come directly from the work of Ptolemy, though, but from later scholars who produced translations and commentaries on his work. Mohammed eb and Musa wrote astronomical texts that explained the motion of the sun, moon, planets, and stars, but without that prime mover. Ahmad Eben Musa also reportedly wrote a work called Book on the Mathematical Proof by Geometry that there is not a ninth sphere outside the sphere of the fixed stars. There katab al Hayal, translated as the Book of Ingenious Devices or Book of Tricks, included one hundred devices along with three others in an appendix. This was probably primarily a Mod's work, but it's credited to all three brothers. These included descriptions of devices from other parts of the world, including Greece and China, as well as the Banu Musa's own original designs. Most of the devices in this book are jugs, flasks, fountains, and oil lamps. There are jugs that can be filled with liquids of different colors, which then pour out each of the colors separately. Thanks to their inner vessels and plumbing, A number of them dispense specific amounts of water or wine, or they refill a basin with a set amount of a liquid. Once that basin has been emptied, the lamps can refill their oil, automatically, trim their wicks, and shield themselves from the wind. This book also includes some devices that we would describe as automata. So one is this arrangement of two basins adjacent to a small animal and a lion, and if only the basin adjacent to the small animal is filled, nothing will happen. But if the basin that's adjacent to the lion is filled, both of the animals drink. There's also one that is a drinking bull, which makes a sound that indicates that it's thirsty. The book also describes one that is a trough filled with water, and when the figurines of twenty animals around it drink from it, nothing happens, But when a bowl figurine that's part of it drinks from it, all of the water disappears. The fountains that are described in this work can produce streams of water in several shapes, including jets, shields, and lilies.

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Speaker 1: Of the valley.

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Speaker 2: The lily of the valley had the water going upward first and then arcing back down, so making the sort of bell like shape of one of those flowers. The shield was similar to that, but wider and flatter. There are also descriptions and diagrams of all these various objects in how they work. They also wrote a treatise called a Book on the Description of the Instrument which plays by itself. This instrument is described as a hydraulic organ or a self playing flute. It used a hydraulic air compressor to force air through a nine hold flute with levers to cover and uncover the holes. The mechanism connected to the levers was a rotating cylinder with adjustable pieces to change which holes were open or closed. It was a little bit like a music box, although the first modern music boxes were not developed until around the seventeen seventies. Because the cylinder could be adjusted to make the flute play different melodies, this is sometimes described as the first programmable machine. The Benu Musa got some criticism for spending so much time on these kinds of devices, even though a lot of their work on this subject had been commissioned by a caliph. People thought these were just novelties with no practical purpose, and that the Banu Musa should be focusing their clearly noteworthy abilities on something more worthwhile. But setting aside the perceptions of whether fun is worthwhile, these objects were based on a lot of technologies that did have practical uses, like self operating valves, timing systems, gear and crank systems, pneumatic controls, and ways to detect and adjust water levels. A lot of these devices had to detect and respond to changes in water pressure or water levels, or they had to maintain steady flows of water or oil or another liquid, and this was particularly important somewhere like Baghdad. Bagdad is surrounded by desert, and in the ninth century when the Banu Musa were living, an extensive network of canals moved water from the Tigris and Euphrates rivers to the city and the surrounding countryside. The canals were used for irrigation, drainage, and transportation, and it was critically important for the water to get where it was supposed to go, but not go where it wasn't a whole sophisticated plumbing system was required to do this, and the fountains were also highly valued in Baghdad, especially by the elite. Fountains were often a focus in gardens and courtyards, and they had both an esthetic and a practical purpose. They looked and sounded beautiful, and they also provided a cooling element in a hot city and a source of water. So a lot of these ingenious devices were based on technologies that allowed people to move and control water in a more immediately practical way. The Banu Musa developed other devices as well, including a clamshell grab that could kind of scoop up earth and was used to dredge rivers and canals, and gas masks and ventilation systems used for people who needed to clean contaminated wells. Much of the Banu Musa's most well known work took place during the rule of tenth Abbasid caliph al Mudawakils. Sometimes al Mudawakil is cited as the person who commissioned the Book of Ingenious Devices, but other sources credit al Mamun. The Banu Musa definitely worked on canals and other public works projects that were commissioned by al Mudawakil. This was connected to some of the disputes that the Banu Musa were involved with, and we will get to that after another sponsor break. Tenth Absid caliph al Mudawakhil was more dogmatic than some of the earlier Absid caliphs had been. He was known for persecuting unorthodox Muslim sects as well as Christians and Jews and adherents of other religions, and for destroying synagogues and churches. He also revived restrictive rules of dress for Christians and Jews. It seems like, at least for a time, the Banu Musa were in this caliph's favor. He was in power from eight forty seven until he was assassinated in eight sixty one, and the Banu Musa did a lot of work that he commissioned during that time. But one of their last projects for him did not go well. He had commissioned a new canal, and while the Banu Musa designed it, they hired a man called Ahmad Ibn Katir al Farragani to actually do the work. Alfragani made an error and how the canal was leveled. Al Muduwakil heard about this error and told the Banu Musa that if the canal did not work properly, he would crucify them next to it. Astronomer and mathematicians. Thenad bin Ali was tasked with an investigation, and he said the brothers work was good, but the water level in the canal was dependent upon the season, and eventually it became obvious that it was not built correctly. That did not become obvious until about two months after al Muduwakil had been assassinated. Though al Mudawakil was also connected to a decades long feud that the Banu Musa had with polymath and philosopher al Kindi, and explanations are not entirely clear about what was really at the root of this feud. Some accounts describe it as part of a greater intellectual feud between mathematicians and philosophers. Others cite the Banu Musa's personal jealousy over al Kindi's private library and the number and rarity of texts that he had in it. Eleventh century scholar al Baruni described this feud as so intense it would turn children's hair gray. It's also possible all of these things were involved in the feud or other things that we haven't mentioned here. Whatever the details were, the Banu Musa worked with al Mudawakil to seize al Kendi's library and have him beaten and expelled from the House of Wisdom. After the whole incident with the canal, Sanad bin Ali arranged to have the library return to him. Sanad bin Ali seems to have had I had a complicated relationship with the Banu Musa. They worked against him because of his overlap with their own research and his work with Alkndi. They tried to keep him isolated from the caliph, but he also saved their lives by vouching for them during this whole canal situation, and the Batu Musa's dislike of al Kindi also had greater political ramifications. The assassination of al Mudawakil started a period known as the Anarchy at Samara, in which a series of caliphs all died by violence. Samara is northwest of Baghdad on the Tigris River, and it was established by the Abbasid Caliphate as an administrative center and military base. At the same time, the Turkish army, which a series of caliphs had relied on for military support, was taking more and more control over the caliphant so to walk through it, Al Mudawakil was murdered by his Turkish guards, possibly with the support of his son and successor, Al Mundasir. Al Mundasir after six months in power, possibly after being poisoned. Then the next caliph, al Mustain, was forced to flee Baghdad and was later executed. His successor, al Mutaz, was chosen by the Turkish army. Al Mutaz was deposed and killed, and his successor, al Mutati was killed after only about a year. All of this happened over the span of nine years between eight sixty one and eight seventy. If you are thinking right about now, this seems like a logical fit for a game with assassins in the name al Mudawakil is killed during the prologue of Assassin's creed kind of sets up the whole thing. The Banu Musa's involvement with this extremely chaotic and violent period was after the death of al Mutasir, who had not named a successor. One of the candidates was al Mustain's brother, who was friends with al Kindy, so the Banu Musa, particularly Muhammad, worked against him promoted al Mustain instead. After al Mustan became caliph, Muhammad worked with him, including being sent to estimate the size of the opposing army when Baghdad was under siege, so they can take that into account when negotiating the terms of al Mustain's abdication. We don't really have much detail about the lives and work of the Banu Musa after this point, and as we mentioned earlier, the likely oldest of them, Muhammad, died in eight seventy three, so that was not long after the end of the anarchy at Samara. We know that they wrote at least twenty books, but many of those books have not survived until today. While the House of Wisdom and the Greater Translation Movement are credited with preserving a lot of ancient texts we would not have otherwise. A lot of the Banu Musa's work was destroyed during the Mongol invasion of Baghdad in twelve fifty eight. Works that still exist today include three complete manuscripts of the Book of Ingenious Devices, several copies of the Book on the Measurement of Plain and spherical figures, copies of on Mechanical Devices or on Mechanics, and one of Book on the Description of the Instrument which sounds by itself. Books that have not survived include Book on the Steelyard, the Book of the First Movement of the Spheres, the Book of the Beginning of the World, and the Book on the Nature of Speech, among others. Their work was really influential during the Islamic Golden Age and beyond. They worked with Muhammad ibn Musa al Korizmi, also known as the Father of Algebra, at the House of Wisdom, although I did find one source that speculated that Mohammed ibn Musa al Korismi and Mohammad ibn Musa ibn Shakir were the same person, which broke my mind a little bit. The Banu Musa's work in mathematics also influenced ibanel Hatham and other scholars during the Islamic Golden Age. We have done episodes on both Alkorismi and ibenel Hatham.

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Speaker 1: In the twelfth century, Gerard of Kremona translated the Banu Musa's work on geometry into Latin and Book on the Measurement of Plane and spherical figures, translated as Libertrium fredom to Geometria, became a standard geometry text in Europe. Leonardo Fibonacci's Practica Geometria was influenced by the Banu Mus's geometry work, and their ingenious devices likely inspired Leonardo da Vinci.

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Speaker 2: Also, in Assassin's Greed Mirage, there's a little quest line involving one of them. Also, you can bring them materials so they can upgrade your tools. One of their books is out there somewhere in the world. I found it anyway, I enjoyed that game. Talk about it more and behind the scenes probably, And I also have some listener mail that is not about this at all. This is from Zach. Zach wrote and the subject line is just gospacho. Hi, Tracy. I listened to today's behind the scenes episode, and the moment you said the word gaspacho, I knew what you were going to say. I was also completely charmed by the availability of gaspacho in Spanish grocery stores. When I visited Barcelona and I went back to Spain last summer, I made a point to seek it out as much as possible. You can also find it in other cities like Sarcoza. It is truly one of the best small pleasures of Spain. I wonder if y'all also encountered the very strange non alcoholic vermuth for children, which has quite a lot of red number five in it, and which I haven't seen anywhere but Catalonia. Take care and happy holidays, Zach. So. I don't think I encountered any non alcoholic vermuth. I feel like it came up in a discussion when we were doing the food tour and you were in a different group with the yeah guide, But I'm not positive I could be misremembering. Yeah, we did experience the beverage that is called vermuth in Catalonia, which is a bit different from what you might just buy in a bottle right in the United States.

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Speaker 1: Please refrigerate it.

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Speaker 2: Be your bottle of Yeah, A lot of people don't refrigerate vermouth.

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Speaker 1: You should anyway, I feel strong, yes is shure? Uh So, Yeah, I don't think.

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Speaker 2: I don't think I encountered a version of vermouth for children. I enjoyed the vermouth that we were served in Barcelona on our on our tasting tour that we went on. We are working on planning the next trip. We are not ready to announce anything about it yet, So thank you so much.

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Speaker 1: Zach for this email.

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Speaker 2: And I'm so glad I'm not the only person who's just so excited about uh gasbatcha at the grocery store. If you would like to write to us about this or any other podcast or a history podcast at aheartradio dot com. We're on social media at miss in History, and you can subscribe to our show on iHeartRadio app and wherever else you'd like to get your podcasts. Stuff you Missed in History Class is a production of iHeartRadio. For more podcasts from iHeartRadio, visit the iHeartRadio app, Apple Podcasts, or wherever you listen to your face for shows