[41] In the centuries leading up to this Romanesque Age, feudal Europe was mired in the relative darkness of the Early Middle Ages. But sophisticated societies thrived to the east and south. Shining like beacons of enlightenment, they inspired and fueled western Europe's progress.

[42, Byzantine Empire, c. 330–1453] Way back in the 5th century, the Roman Empire had fallen in the West. But it lived on in the East, eventually becoming the Byzantine Empire. Byzantium remained Christian and its capital was Constantinople — today's Istanbul. Throughout the Early Middle Ages, with its imposing walls, for centuries, Constantinople was Europe's leading city — ruling a vast empire that was relatively prosperous and stable.

[43, Hagia Sophia, 537, Istanbul] While western Europe built nothing nearly as grand during this period, Constantinople constructed this magnificent church — Hagia Sophia. (The minarets were added later when it became a mosque.) Built around the year 500 on the grandest scale possible, it symbolizes Byzantium's glory days. They used ingenious technology: a massive central dome supported by half domes that was the biggest anywhere — and remained that way for nearly a thousand years. While a place of Muslim worship today, for centuries Hagia Sophia functioned as a church — perhaps the most exquisite church in all of Christendom.

[44] The church tried to recreate the glory of the Byzantine Heaven. The vast interior gives the impression of a golden weightless shell, gracefully disguising the massive overhead load. Forty arched windows shed a soft light on the interior, showing off the ancient building's Christian legacy that has endured the test of time.

[45] The Italian city of Venice is a reminder that the more advanced Byzantine culture reached westward, far into Europe.

[46] In the 11th century, St. Mark's Basilica was topped with Byzantine-style domes. Its decoration reflects that connection with the East.

[47, Four Tetrarchs sculpture, c. 300, Venice] The basilica's fanciful façade is decorated with mismatched columns and statues which were largely pillaged from elsewhere during the crusades. The style? I'd call it "Early Ransack." A good example of such plunder is this ancient Roman statue carved of purple porphyry — a precious stone quarried in Egypt and symbolic of power.

[48] By the way, the Crusades were a big deal back in the 12th and 13th centuries. Lots of important art was pillaged from Constantinople by rampaging crusaders — those Christian armies that stormed through Muslim territory in a series of religious wars through much of the Middle Ages. While their mission was to be sure Christian pilgrims had access to their Holy Land in Jerusalem, the so-called "Holy Crusades" often got sidetracked with the rape, pillage, and plunder dimensions of war.

[49] Of all the plundered art on this church, perhaps the grandest prize was a set of horses which overlooked Venice's main square. The precious originals — like so much of Europe's greatest art — are now inside, safely out of the elements.

[50, Horses of St. Mark, 300 BC–AD 400, Venice] These much-coveted and exquisitely cast ancient bronze horses — so realistic — are certainly well-traveled. According to legend, they were made for the Greek ruler, Alexander the Great, in the fourth century BC, taken by Emperor Nero to Rome, and then brought by Emperor Constantine to Constantinople, where the Venetian Crusaders stole them, took them home, and parked them here in their main church.

[51] The church's entire interior glitters with gold-leaf mosaic work. In good medieval tradition, it's slathered in the predictable Bible stories. The story of Adam and Eve, one of the most popular, unfolds like a cartoon strip: Adam lonely in the garden, the creation of Eve, and then trouble — from apple…to fig leaf…to banishment.

[52] The Venetians learned mosaic technique from the Byzantines, who inherited it from the ancient Romans, who paved their villas with mosaics. The Byzantines perfected the gold color, made of bits of glass with gold-leaf baked in. These reflected the light to help illuminate an otherwise dark church, giving it the golden glow of the Byzantine Heaven.

[53, Pala d'Oro, 10th–12th century, St. Mark's Basilica, Venice] St. Mark's Byzantine-style altarpiece is a stunning wall of gold, studded with precious rubies, emeralds, and pearls. Some two hundred enamels — plundered from Constantinople — depict prophets, saints, and angels. And in the glorious center of it all sits Jesus, the Ruler of the Cosmos.

[54] With its stunning art, St. Mark's Basilica is a vision of a highly cultured world that had been established by the Romans, was preserved by the Byzantines, and was now being re-infused into western Europe.