The Banu Musa

Episode Transcript
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Speaker 1 (00:01):
Welcome to Stuff You Missed in History Class, a production
of iHeartRadio.

Speaker 2 (00:11):
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

(00:32):
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

(00:54):
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.

(01:16):
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.

(01:37):
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

(01:57):
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

(02:19):
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

(02:41):
Academy of Science, mainly functioned as a library and a
translation center.

Speaker 1 (02:47):
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

(03:07):
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

(03:28):
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

(03:50):
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

(04:12):
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

(04:36):
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.

Speaker 2 (04:47):
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

(05:10):
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

(05:32):
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

(05:57):
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

(06:17):
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,

(06:41):
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

(07:03):
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

(07:24):
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

(07:46):
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,

(08:08):
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

(08:31):
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,

(08:53):
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

(09:14):
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

(09:35):
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

(09:58):
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

(10:20):
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

(10:41):
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

(11:03):
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

(11:25):
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

(11:50):
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.

(12:10):
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

(12:33):
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

(12:55):
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

(13:17):
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.

(13:39):
The fountains that are described in this work can produce
streams of water in several shapes, including jets, shields, and lilies.

Speaker 1 (13:47):
Of the valley.

Speaker 2 (13:48):
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

(14:11):
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

(14:33):
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

(14:54):
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,

(15:15):
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

(15:37):
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

(15:59):
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

(16:20):
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

(16:41):
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

(17:03):
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

(17:35):
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

(17:58):
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

(18:19):
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.

(18:39):
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

(19:01):
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

(19:24):
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

(19:46):
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

(20:08):
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

(20:30):
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,

(20:51):
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

(21:11):
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

(21:32):
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,

(21:56):
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

(22:17):
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

(22:38):
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,

(23:03):
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

(23:24):
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

(23:47):
influenced ibanel Hatham and other scholars during the Islamic Golden Age.
We have done episodes on both Alkorismi and ibenel Hatham.

Speaker 1 (23:55):
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,

(24:16):
and their ingenious devices likely inspired Leonardo da Vinci.

Speaker 2 (24:21):
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.

(24:43):
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

(25:03):
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.

(25:25):
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

(25:47):
different from what you might just buy in a bottle
right in the United States.

Speaker 1 (25:52):
Please refrigerate it.

Speaker 2 (25:54):
Be your bottle of Yeah, A lot of people don't
refrigerate vermouth.

Speaker 1 (25:58):
You should anyway, I feel strong, yes is shure? Uh So, Yeah,
I don't think.

Speaker 2 (26:03):
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.

Speaker 1 (26:24):
Zach for this email.

Speaker 2 (26:25):
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

(26:50):
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