The aqueducts and cisterns of Constantinople

The impressive walls of Constantinople

This video explores the land walls of Constantinople, built on the orders of Theodosius II in the mid-fifth century. They consisted of a triple line of defenses, studded with hundreds of towers and supplemented with a moat. The walls were besieged dozens of times, but were only broken in 1453 by the power of Ottoman cannons. As repaired by the Ottomans, the walls are still largely intact today.

The underground cities of the Byzantine Empire

This TED-Ed video explores the mysterious cave cities of Cappadocia. Although their oldest sections may go back to the Bronze Age, most of these subterranean complexes were excavated during the Byzantine period, when the locals went underground to take shelter from Arab raiders. Monasteries were also cut into pinnacles of the local tufa, and decorated with frescoes that have often survived to the present.

In 1963, a basement renovation in Turkey revealed a passageway to a hidden, multilevel underground city that once housed as many as 20,000 people.

Eleven aqueducts funneled water to Rome's 1 million inhabitants

The Roman Empire's capital city was home to about one million people at its peak and managed to provide running water to many of its homes, fountains, and public baths. This was made possible by the 11 aesthetically grand aqueducts that poured into ancient Rome from the countryside.

Visualizing Byzantium in the year 1200

This is a computer reconstruction of the Byzantine capital at its apogee, just before the Fourth Crusade. Alongside detailed renderings of the Hippodrome and Hagia Sophia, it includes dozens of the imperial city’s less famous monuments, many of which can still be found in modern Istanbul. The reconstruction is a work in progress, and the Byzantium 1200 X account routinely posts updates.

The first coffeehouse opened in Constantinople

Coffeehouses began opening in modern-day Istanbul sometime in the 1500s. These cafes quickly became invaluable spaces for gathering and exchanging news and ideas.

The Alhambra’s medieval water system powered a palace-city

Built over centuries by Islamic rulers in medieval Spain, the Alhambra used canals and pressurized tanks to move water throughout the complex. Its sophisticated system supplied fountains, baths, and gardens, showcasing advanced medieval engineering.

The unusual connection between Venice and Byzantium

This article explores the complicated relationship between Venice and the Byzantine Empire. Venice grew up in the shadow of Byzantium, serving as a trade partner and faithful ally for centuries. Gradually, relations grew hostile, and Venetian ships would carry the Fourth Crusade to its fateful rendezvous with Constantinople. Visitors to San Marco can still see marble and porphyry from Constantinople, built into the walls of Venice’s preeminent church.

Exploring the Hippodrome of Constantinople

The Hippodrome had room for about 80,000 spectators (more than the Colosseum, but less than Rome’s Circus Maximus). It was simultaneously Constantinople’s premier entertainment venue and its greatest political theater: the emperor routinely watched the games, and sometimes communicated with the crowd through a herald. The worst riot in Byzantine history, the Nika Revolt, began when the factions of the Hippodrome united in opposition to Justinian.

Hagia Sophia, Istanbul's most famous and controversial landmark

A short video about the iconic Byzantine church. Still Istanbul’s most famous and, since its reconversion to a mosque, most controversial building. The recognizable dome has partially collapsed several times over the centuries, but remains a marvel of engineering. The mosaics, though fragmentary, are among the finest ever created and trace both the gradual evolution and the remarkable continuity of Byzantine art.

The Chora Church, the height of Byzantine art

The Palaeologan Renaissance took place in the final centuries of Byzantium, and in the face of steep political and economic decline. Perhaps the movement’s most famous artistic product is the Chora Church in Istanbul. Renovated in the early fourteenth century by Theodore Metochites, a learned court official, the church features remarkably vibrant mosaics and frescoes. Although the building was recently reconverted into a mosque, most of its decorations are still visible.

Rise and fall of the Byzantine Empire in 60 seconds

In 330 CE, Emperor Constantine made the bold move of shifting the Roman capital to Byzantium and renaming it Constantinople. This decision helped shape the Eastern Roman Empire, or what we now call the Byzantine Empire. Here’s how the city rose to global prominence, and why its legacy lingers today.

The high-tech mechanisms of the Roman Colosseum

The Roman Colosseum is one of the most iconic amphitheaters in the world and still partially stands today. Aside from its sheer size, the arena was equipped with some of the most high-tech engineering from the classical world, including sophisticated lifts, a huge retractable awning, and an underground network of tunnels, elevators, and trapdoors.

The ancient Egyptians built prototypes of the modern Suez Canal

The idea to facilitate trade between the Mediterranean Sea and the Red Sea and connect the Eurasian continent was apparent even to pharaohs in the second millennium BCE. Though no physical traces remain, contemporary accounts attest to early, shorter versions of the canal, including from Herodotus.

The mosaics of San Vitale, Italy's Byzantine city

This video explores the unique artistic heritage of Ravenna, the center of Byzantine power in Italy. The city’s churches and baptistries still sparkle with a dazzling array of Byzantine mosaics. The most famous of these, in the Church of San Vitale, show Justinian and his wife Theodora with their courtiers. A visit to Ravenna – or at least a look at this video – is highly recommended to anyone interested in Byzantine history or art.

Estimate the costs of an ancient Roman vacation

The century-long debate over religious images in Byzantium

The iconoclast controversy, which tore Byzantium apart in the eighth and ninth centuries, centered on the use of sacred images (or icons) in Christian worship. The Iconoclasts (literally, “icon smashers”) regarded sacred images as sacrilegious; their opponents, the Iconophiles (“icon lovers”), defended icons as aids to personal devotion. After decades of struggle, the Iconophiles prevailed; their victory ensured that icons, and the brilliant mosaics inspired by them, remained a feature of Byzantine churches.

The Greek city of Alexandria in Egypt helped form the template for modern cities by considering function, commerce, culture, and politics.

Why Water Towers Are Built This Way

A map of the Byzantine Empire

This map, hosted on the World History Encyclopedia, shows the Byzantine Empire in four eras. The area shaded dark purple is the original Eastern Roman Empire. The light purple areas represent the conquests of Justinian. The dark purple line surrounds the middle Byzantine Empire. The hatched area, finally, indicates the small “Latin Empire” established after the Fourth Crusade.

Why only one of the seven wonders of the ancient world still exists

Greek writers recorded lists of great structures that were later codified by Renaissance writers. The definitive list includes the Colossus of Rhodes, the Giza Pyramid (the only existing one today), the Hanging Gardens of Babylon, the Temple of Artemis at Ephesus, the Statue of Zeus at Olympia, the Mausoleum at Halicarnassus, and the Lighthouse of Alexandria.

Synchronized swimming dates back to Ancient Rome

Known for gruesome gladiatorial contests, ancient Rome's aquatic spectacles may have been even more over-the-top. This article dives into the art of synchronized swimming in ancient Rome. Lakes were dug and amphitheaters flooded to provide space for aquatic reenactments of naval battles and artistic performances. Swimmers playing the role of water nymphs would create elaborate shapes, including ships with billowing sails.

What was the Fourth Crusade?

Originally destined for Jerusalem, the Crusaders became entangled in a Byzantine civil war, and found themselves besieging the greatest city in Christendom. After breaching the sea walls and subjecting the city to the worst sack in its history, they installed a Flemish nobleman as Latin emperor of Constantinople.

The Erie Canal runs 363 miles from Albany to Buffalo

Mostly using the low elevations of the Mohawk River Valley, the canal project connected the Great Lakes to the Atlantic seaboard for the first time. This site has a series of old and new maps of the canal.

The original canal had 83 different hand-operated locks

Locks are gated chambers that raise and lower boats between stretches of water at different levels. On the Erie Canal, 83 such locks managed a 565-foot elevation change from the Hudson River to Lake Erie.

The Great Lakes hold almost 20% of the world's surface freshwater

Formed by retreating glaciers, the Great Lakes system feeds Niagara Falls through the Niagara River. Together, the lakes contain about 23 quadrillion liters (5,400 cubic miles) of water, enough to cover the land portion of the continental US to a depth of 3 meters (9.84 feet).

Wildlife use Rome's sprawling archaeological sites as urban havens

The Italian capital features some of the world's most famous monuments as the inheritor of ancient Rome's grandeur. This photo essay explores the city's vibrant collection of wildlife, including long-concealed native crabs, peregrine falcons, and the beaver-like nutria.

The top 10 Byzantine emperors

"The History of Byzantium" podcast, hosted by Robin Pierson, tells the entire history of the Byzantine Empire, from Constantine to the fall of Constantinople. As of this writing, it isn’t quite done, but there are more than 300 episodes to peruse. The episode linked here, with guest Anthony Kaldellis, ranks the top 10 Byzantine emperors.

Water from four Great Lakes feeds Niagara Falls

Niagara Falls is powered by water from Lakes Superior, Michigan, Huron, and Erie. The Great Lakes basin spans over 260,000 square miles and holds nearly 20% of the world's surface freshwater—about two-thirds of which passes over the falls.

Travel the 363-mile Erie Canal, the waterway that cut freight costs by 90% and opened the American frontier.

Learn how aquifers and wells provide the largest reserves of accessible freshwater on Earth

Roughly a third of Earth's freshwater is stored underground in aquifers—permeable and porous rock formations where water naturally flows from the Earth's surface and accumulates. About half of this groundwater is accessed through wells, a feat of engineering used for thousands of years.

Toronto's downtown has 18 miles of underground pedestrian tunnels

Known as the "Path," these tunnels have helped reduce pedestrian traffic on Toronto's busy downtown streets for over a century. They were first built by local business owners, prompting a network effect of add-on tunnels.

How Byzantine scholars supercharged Renaissance Italy

A brief survey of how Byzantine scholars changed the course of the Renaissance by introducing Classical Greek literature to Italy. These scholars and their students were responsible for translating, interpreting, and printing many of the most fundamental texts in the Western tradition. Without their efforts, the Italian Renaissance and Western thought would have been immeasurably poorer.

How the Code of Justinian formed the basis of modern law

This video explores the significance of Justinian’s Corpus Juris Civilis. The most important component of the Corpus, the Digest, collected the opinions of eminent Roman jurists. The Digest went on to become the legal framework of medieval Europe, and the basis for the civil codes used across two-thirds of the globe today—an underappreciated legacy of Byzantium.

Infrastructure projects in New York are much more difficult today

The Erie Canal was one of the most ambitious infrastructure projects in American history. Many have said such an effort would be impossible today. This article explores why that is the case and ponders the future of large-scale American infrastructure development.

Being a Byzantine emperor

The Byzantium and Friends podcast, hosted by Anthony Kaldellis, surveys current research in the history of the Byzantine Empire and its neighbors. In each episode, Professor Kaldellis interviews a scholar about their recent work. The cumulative effect is to reveal a world much more complex, and much more interesting, than the Byzantium found in traditional surveys. The linked episode considers the perks and pitfalls of being a Byzantine emperor.

The Atlantic Ocean is home to the world's largest waterfall—the Denmark Strait cataract—which is more than three times the height of the largest land-based waterfall.

Essential pipes, sewers, and cables lie buried beneath New York City

The Department of Design and Construction offers a tour of its work sites, explaining the complex systems that exist underground. Gas, electrical, telecom pipes, and many others, sprawl out underneath the entire city, with dozens of maps that help workers know where they're placed. This layout is unusual compared to the rest of the country, where wires are often present and visible above ground.

A medieval Italian visits Constantinople

In the tenth century, the Holy Roman Emperor Otto I sent Liudprand of Cremona, an Italian bishop, to Constantinople on a diplomatic mission. He was not successful. But the very undiplomatic report he sent back to the emperor about his experiences provides a unique – and often very entertaining – look at life and ceremony in the Byzantine capital, dramatically different from anything in Liudprand’s Italy.

Structures from ancient Rome have endured for millennia because tiny pieces of lime in Roman concrete enabled it to self-heal and prevent cracks from spreading when exposed to water.

Explore the system of ancient Roman roads with this interactive

The Itiner-e map includes unpaved secondary roads that connected farms and towns to the empire's primary routes. Explore routes, view three-dimensional elevation, and compare the old roads to contemporary ones with this sprawling interactive project.

How LA brought water to its booming population

By the turn of the 20th century, Los Angeles had grown from a dusty, crime-ridden pueblo into a thriving metropolis. The only problem was that it was growing too fast. Here's the story of how the booming town created a massive water infrastructure to redirect area rivers to its residents.

Roman roads have lasted for millennia and were key to its military might

Known for their almost absurd straightness, Roman roads connected the empire's armies, messengers, and traders as imperial administrators sought to keep down rebellion and build up Roman wealth. Rome's highways were expertly engineered, well-patrolled, and easy to navigate.

The rise and fall of the Byzantine Empire

A short but informative TED-Ed video summarizing the most important aspects of Byzantine civilization: how it all started, why Constantinople was so special, a few remarkable Byzantine authors (including Princess Anna Comnena, historian of her father’s reign), the Ottoman conquest, and why don’t just call the Byzantines “Romans.”

Fascinating 3D animation shows how Romans built roads

Highly efficient engineering and materials production allowed Roman administrators to lay down nearly 50,000 miles of roads across the ancient empire. These roads were built so effectively that many are still around today. Watch this quick 3-minute video to see how they did it.

The Panama Canal was the first to use a lock-and-lake system on a massive scale.

During the Medieval Period, urban populations grew significantly

As workers moved from fields to cities throughout the era, large metropolises of enduring strategic importance were formed from Paris, France, to Baghdad, Iraq.

Why are ancient ruins underground?

When cities fall into disrepair, it's often easier to flatten what you can and build on top. This is why modern archaeologists frequently discover ruins underground, revealing generational layers of cities rebuilt over time. This video explores major examples of this principle, from ancient Troy to even modern Seattle.

The sewage of New York City

Residents of the five boroughs of New York produce 1.3 billion gallons of wastewater everyday. Seventy miles of sewer pipes, first built in the mid-1800s, feed the sewage to 14 wastewater treatment and recovery plants where the waste is treated back to viable, drinkable water. See what shouldn't go down the toilet here.

Ancient Romans took trips to the coast to beat the heat and relax.