Byzantine Architectural Marvels: Hagia Sophia, Sergius & Bacchus, Gracanica
Slide 1
Byzantine Architecture
We are going to look at three examples of Byzantine architecture in this lecture:
- Hagia Sophia, which used a system of pendentives, domes, half-domes, and exedrae to create one of the world’s greatest examples of engineering
The Church of Saints Sergius and Bacchus, which utilized a domical vault to span its central space
Gracanica Church, which offers an excellent example of a cross-in-square church
- The major goal of Byzantine architecture was to dematerialize space. Dematerialization means that the confines of the space – walls and ceilings – become therefore less distinct than they usually are, meaning that you are not quite certain where they are. Thus space is dematerialized or made less material. For instance, the cheapest modern way to dematerialize space is to have walls – and even a ceiling – covered in mirrors. We are going to look at far more complex examples. The reason Byzantine architecture wanted to dematerialize space was to bring you – the visitor – in an otherworldly state of mind so that you could worship as Christian better.
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- Hagia Sophia was completed as a church in 537 and remained so until it was turned into a mosque in 1453 when the city was conquered by the Ottoman Turks. Since 1935 it has been a museum.
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The major features of Hagia Sophia as seen in section
- A = an exedra, which is a large, half-cylinder volume capped by a half-dome: an excellent example of absolute symmetry. We use the term exedra only when speaking about a truly monumental-size half-cylinder. This exedra happens to serve as the apse, which in churches is where the altar usually is. B and H also are exedrae (plural).
- C and G = half-domes
- D = a pendentive
- E = the central dome
- F = one of two flat walls on the sides of the building where there are no half-domes and exedrae
- I = inner narthex
- J = outer narthex
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Hagia Sophia, Constantinople (today Istanbul), 532 A. D.
See if you can locate all the parts from the previous slide in this image.
- Look at the list of elements on the previous slide and realize how superbly the lessons of the arch and its subsequent forms have been used here! If you had to place arrows indicating how the weight is distributed, how would you draw them in a section? See the next slide, which shows some of the arrows drawn.
- Hagia Sophia also contains aspects of both longitudinal and central plan churches, which you can see on the plan to the right:
- Longitudinal aspect: central dome plus two
half-domes creates a nave flanked by one aisle on each side
- Central aspect: main body of the church is almost a square and the central dome dominates
Hagia Sophia, Constantinople (today Istanbul), 532 A. D.
- A closer look at the section
- Recalling what you know about the architecture of arches, realized that the two half-domes serve to distribute much of the central dome’s weight safely to their exedrae, which further distribute the weight downward to the ground.
- The two sides that do not have half-domes therefore are the most stressed regarding weight and prone to collapse.
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Hagia Sophia, Constantinople (today Istanbul), 532 A. D.
A closer look at the plan:
- Light gray = outer narthex
Dark gray = inner narthex
- Yellow = dome
- Purple = half-domes
- Green = exedrae capped by half-domes
- Red = apse
- Blue = massive external buttresses. Notice where most of them are: along the sides without half-domes.
- Use your knowledge of where half-domes and massive buttresses occur to help you identify photographs of this building as well as understand how the massive weight of the central dome is dispersed down to the ground.
- The plan is shown enlarged on the next slide to help you study this important building.
Study this cutaway rendering to help you remember the different parts of this very important building!
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Here is another view to help you.
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Hagia Sophia, Constantinople (today Istanbul), 532 A. D.
- Views of the central dome, half-domes, and external buttresses. Ignore the cluster of smaller buildings that has accrued over the centuries. We will only be studying the original building.
- As far as the numbers below are concerned, you do not have to memorize them: they are here to give you an indication of this building’s massive size.
- The church itself measures 260 x 270 feet; the dome rises 210 feet above the floor and has a diameter of 110 feet. The nave is 135 feet wide, more than twice the width of the aisles which measure 62 feet.
- In its heyday Hagia Sophia was served by 80 priests, 150 deacons, 60 subdeacons, 160 readers, 25 cantors and 75 doorkeepers!
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- The central dome with flanking half-domes
- Notice how shallow the dome is and how many windows pierce it: both aspects contributed to its perilous stability and history of collapsing twice. Each time it was rebuilt, it was made slightly higher so that better weight distribution could occur.
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- Views of the inner narthex
- Aspects of Roman architecture:
Concrete and brick construction with revetments of marble covering inside walls
Groin vaults
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- Revetments in the inner narthex
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- Revetments and mosaic in inner narthex
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- General view of the interior
- The central dome and one half-dome can be seen, as well as the apse in the far distance
- The two side walls that do not contain half- domes also can be see. Notice how many windows they contain.
- This view is taken from the gallery above the entrance from the inner narthex.
- The central dome
- Notice how the 40 windows cut into the dome make the dome appear to float and contribute to an other-worldly atmosphere.
- The dome is one of the greatest engineering triumphs in history, perhaps outranking even the Pantheon in Rome, due to the use of pendentives.
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- Views of the central dome
- Most interior decoration has been covered over since the church became a mosque in 1453.
- The original dome was slightly shallower than the present one, which was one reason why it collapsed.
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- In this view, the apse is in the center with an exedra flanking it on each side. Notice how a barrel vault leads to the apse, whereas the exedra with their half-domes start immediately at the base of the giant half-dome above.
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- Close-up of the apse
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Views of the nave arcade with the gallery above
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Here is another view looking upward. See if you can identify the following parts:
central dome, half-domes, exedrae, pendentives, flat walls on sides without half-domes, the exedra that serves as the apse. Another question: how many pendentives do you see in this image?
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There are 7 pendentives visible: numbers 1 – 7.
There are 3 partial pendentives visible: letters A – C. Can you explain why these are only partial pendentives? Remember: one of the goals of this course is to train you think spatially and recognize spatial and structural elements, regardless of what angle a photograph is taken from!
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Church of Saints Sergius & Bacchus, Constantinople (Istanbul), 530
In this church, we have two main goals:
- To train your eyes to describe the details of a plan. Look at these features:
Overall shape is a somewhat crooked square
- An ambulatory (green) wraps around the central space, consisting of:
- 4 exedrae or curved portions tinted blue, each containing two columns.
- 4 straight portions tinted pink, each containing two columns. The final straight portion is free of columns, for it leads to the chancel (orange) and apse (yellow).
- To understand what a domical vault is.
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- The view on the right is toward the chancel and apse. Note that the chancel is defined by a barrel vault. Flanking this on each side is an exedra capped by a half-dome.
- In the plan to the left, the octagonal base is outlined in red, as it is in the photo on the right. Above this octagonal base is not a dome, but something completely new.
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This is our first instance of a domical vault, which is a vault with flat surfaces that rise up from each side of a polygonal base and then curve upward to meet of the top, forming what only appears to be a dome. No pendentives are used here!
- The octagonal base has remained an octagon, as the blue tinted area shows. No perfect circle has been formed upon which a dome might have been placed, for no pendentives were used. We therefore have to make good with 8 large panels that rise up to meet one another to form a domical vault. Three of the panels have been tinted and labeled A, B and C in the photo and diagram. Notice how the spandrels and piers below match the octagon’s panels above.
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Let’s look at each part to help you a bit.
- Below: 3 of the 8 panels are shown. Ignore the decorations and lines within each panel: these were done to disguise that this is not a true dome, but a domical vault. You can locate the center of each panel by looking for a window. Each panel is flat – look at its base along the blue line – and it maintains its flatness as it curves inward. Think of propping up a piece of paper but letting the top portion droop a bit as the figure below shows. Notice how the paper is curving in only one direction: it still maintains flatness in another direction. Now take eight of these sheets, arrange them in an octagonal fashion, let them droop toward one another, trim the excess paper, and you will have an octagonal domical vault (whew!).
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- So what is the difference between a pendentive and a panel of a domical vault? The pendentive curves in two directions: laterally and upward, whereas a panel of a domical vault remains flat laterally and curves only in an upward manner. Study and compare the two images below. This is an excellent exercise in thinking spatially, which you need as architects!
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- Here’s another way to look at what makes a pendentive different from a panel of a domical vault.
Pretend that you have an orange.
- Draw a triangle on it and then carefully cut along those lines but only deep enough so that you can remove that triangular piece of the orange’s skin.
- Now imagine that you are holding that triangular piece of orange peel in you hand. It still retains its curve, and in fact, it curves in two directions: laterally (side-to-side) and longitudinally (top-to-bottom).
- Now pick up that triangular piece of orange peel in your other hand, holding your thumb on the bottom point of the triangle and your forefinger along the top edge. Rotate the piece so that you are staring at its inner side (the white side).
You are now staring at a pendentive!
- Contrast this with holding one of the eight pieces of paper that we used two slides ago to construct our domical vault.
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- Left: the angled spandrel. Remember: the two sides of the spandrel (think of folding a piece of paper vertically) rise straight upward without curling inward. Therefore no pendentive is created – and the blue line of the octagon reminds us of this. This image is enlarged on the next slide.
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- A more recent view of Sergius and Bacchus, taken under modern lighting conditions that were installed so that restoration work could be performed. The complex beauty of the domical vault can be seen.
- The diagram of an octagonal domical vault is repeated below to help you understand the structure of this church.
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- View of the angled piers and angled spandrels
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- View of an angled pier. See if you can spot the angle and then go to the next slide.
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Gracanica Church, Republic of Kosovo (formerly part of Serbia), 1320
- This church is an example of a cross-in-square church, but before we examine what a cross-in-square building is, let us look at two plans.
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Gracanica Church, Republic of Kosovo (formerly part of Serbia), 1320
- There are six domes in the church: 4 domes at corners, 1dome visible both inside and outside, and 1 dome seen only when one is inside the church.
Near-right: plan emphasizing the central dome (red) that is visible both inside and outside
- Far-right: plan emphasizing four smaller domes at corners (red) that are visible both inside and outside
- Green: the sixth dome that you can see only on in the inside.
- The purple area at the bottom is a very elaborate narthex with its own dome. Notice how enormous this narthex is in comparison to the rest of the church. This was so that court officials could gather before proceeding into the sanctuary.
- This was a royal church, built by King Milutin of Serbia, which accounts for its complex, sophisticated design and lavish interiors.
Gracanica Church, Republic of Kosovo (formerly part of Serbia), 1320
Gracanica is an example of a cross-in-square church, of which a typical schematic drawing (not Gracanica) is shown to the right.
- How to identify a cross-in-square church:
- Blue = cubical (cube-like) on the first level that is square in plan
Green = cruciform (cross-like) on the second level
Yellow = drum
Red = dome rests at the intersection of the arms of the cross
- Four smaller domes (red) or vaults placed in-between the arms of the cross at the corners
- Review: plain old Greek cross (not cross-in-square) seen at Mausoleum of Galla Placidia in Ravenna (bottom right). The difference is the first level:
- In a plain old Greek cross, it actually is in the shape of a Greek cross.
In a cross-in-square, the first level is in the shape of a square, and only on the second level does it step back to become a Greek cross in shape.
- Remember: this is a superb example of a cross-in-square church. Know this – do not let the large narthex fool you! Being a royal church, Gracanica is more elaborate than the schematic drawing on the right. All five domes, for instance, that are expressed on the outside are mounted on elaborate octagonal drums.
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- Another aerial view lets us see the different components of the church very clearly. This photo was taken before the church’s restoration. Can you identify each one without returning to the previous slide?
- Below is another view.
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- Approaching the narthex of the Church
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- Left: view of the narthex, three of four corner domes, and central dome
- View of the apse (encased in a trapezoid), two corner domes, and central dome.
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- A winter view and close-up of the central dome
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- Once we pass through the narthex and into the sanctuary, we realize that every surface is covered with frescos (paintings on walls). So elaborate and extensive are the frescos that the church is considered an United Nations World Cultural Heritage site. As a result, a massive program to digitally photograph every square inch is in progress, as well as restoration efforts.
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In the rear of the image is the iconostasis, a screen that is covered with priceless icons and paintings. It is tinted blue in the plan below. In the Serbian Orthodox faith, the priests would stand behind the iconostasis while conducting the service, while the worshippers would be on the other side, underneath the dome. The image below right shows priests conducting a service at Gracanica, and behind them is the iconostasis.
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- A closer view of the iconostasis also brings into view some of the piers of the church and their frescos.
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- A glance upward begins to reveal the magnificence of this other-worldly church. Thousands of fresco images rise upward toward the five domes, almost disappearing in the milky darkness.
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- A view looking downward is no less impressive, and from this angle we can see behind the iconostasis to the holiest part of this royal church.
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- Pendentives have been used to support the drums and domes. This image is an excellent one to study: not only are the four pendentives clearly shown, but they are clearly separated from the arched walls beneath by the red lines.
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- A close-up of a pendentive illustrates one of the frescos. Here the Holy Spirit, symbolized by the feathers and wings of a bird, mysteriously gazes at us. Remember: this fresco is over 700 years old and has survived numerous wars!
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- If we perch ourselves right on top of the iconostasis (the white structure at the bottom), we can peer into the holiest part of the church, the apse and altar. The altar itself is very small, for the magnificent frescos not only dominate but also tell many stories.
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- From this height, we get a clear view of the apse and its half-dome, as well as the deteriorating condition of some of the frescos.
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- If we return to the main body of the church and look upward, we will see several barrel vaults decorated with frescos. This one is politically significant, for shows Christ flanked by angels delivering crowns. The message is clear: Serbian royalty rules with the approval of God.
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- The same religious-political theme appears in other parts of the church as well. Here two angels are delivering a crown and jewel-encrusted garment to drape over the shoulders of the king. This theme was common throughout human history, from ancient Egypt until quite recently: rulers were ordained by God – or the Gods – to rule.
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- On another barrel vault, an angel delivers a crown to King Milutin, who holds in his hands a model of the Church. The sanctity of the church therefore is made clear: the king, who rules directly by the grace of God is the builder of this church.
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- On the other side of the same barrel vault is a depiction of Queen Symonida, with an angel delivering a crown to her as well.
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Gracanica Church: restoration in progress
- These panoramic photos illustrate a section of the church before restoration and another section after restoration. The restored brilliance of the colors provide a glimpse of how this important world landmark will look once the work is completed.
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- This view shows the main dome after its recent restoration. The pendentives, drum/clerestory, and dome clearly can be seen.
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- If we step back a bit, we now see how most of the church has been restored. Barrel vaults and pendentives are visible, as are three of four reinforcing metal bars that have been placed to stabilize the structure on account of its age. These can be seen right below the pendentives of the central dome.
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