The World's Greatest Churches

• Introduction
• Chapter 1 Hagia Sophia, Istanbul
• Chapter 2 St. Peter’s Basilica, Vatican City
• Chapter 3 Notre-Dame de Paris, France
• Chapter 4 Chartres Cathedral, France
• Chapter 5 Milan Cathedral (Duomo di Milano), Italy
• Chapter 6 Cologne Cathedral, Germany
• Chapter 7 Florence Cathedral (Santa Maria del Fiore), Italy
• Chapter 8 Westminster Abbey, London
• Chapter 9 Sagrada Família, Barcelona
• Chapter 10 Church of the Holy Sepulchre, Jerusalem
• Chapter 11 Basilica of Our Lady of Aparecida, Brazil
• Chapter 12 Seville Cathedral, Spain
• Chapter 13 Cathedral of Santiago de Compostela, Spain
• Chapter 14 St. John’s Cathedral (Cathedral of St. John the Divine), New York
• Chapter 15 Basilica of Our Lady of Peace, Yamoussoukro, Côte d’Ivoire
• Chapter 16 Nidaros Cathedral, Trondheim, Norway
• Chapter 17 Rock-Hewn Churches of Lalibela, Ethiopia
• Chapter 18 St. Mark’s Basilica, Venice
• Chapter 19 Canterbury Cathedral, England
• Chapter 20 Painted Monasteries of Bucovina, Romania
• Chapter 21 Basilica of St. Francis of Assisi, Italy
• Chapter 22 Liverpool Cathedral, England
• Chapter 23 Chora Church (Kariye Mosque), Istanbul
• Chapter 24 Churches of Chiloé, Chile
• Chapter 25 Urnes Stave Church, Norway

Across continents and centuries, churches have stood as extraordinary manifestations of humanity’s quest for meaning, beauty, and community. The World’s Greatest Churches is a guided journey through some of the most awe-inspiring sacred structures ever built. From the towering spires of Gothic cathedrals to the carved monoliths of Ethiopia, each chapter of this book uncovers a unique story of faith, creativity, and resilience, inviting readers to experience the splendor and significance of these remarkable places.

What qualifies a church as “great”? This is a complex question, for greatness encompasses not only architectural grandeur, but historical depth, artistic achievement, and enduring spiritual and cultural importance. Some of these churches are renowned for their vast dimensions, capable of hosting tens of thousands of faithful; others for their innovative designs or precious relics that have drawn pilgrims for generations. Still others are celebrated for the ways in which they reflect and shape the societies around them, becoming indelible parts of national identity.

Churches are more than mere buildings—they are vibrant centers, evolving through periods of triumph and turmoil. In times of war and peace, prosperity and hardship, these houses of worship have often served as the beating heart of communities, witnessing countless personal milestones and public events of global consequence. Whether as the site of a king’s coronation, a city’s founding, or a miraculous healing, great churches illuminate the ongoing relationship between the sacred and the everyday.

Throughout history, these objects of devotion have also been patrons of the arts, spiritual sanctuaries, and classrooms written in stone, glass, and paint. They have preserved and showcased dazzling mosaics, stained glass, sculpture, and frescoes, often standing as the best surviving testaments to entire eras of artistic flourishing. The treasures and relics housed within their walls have transformed them into epicenters of pilgrimage, drawing millions seeking solace, healing, or communion with the divine.

The twenty-five churches explored in the following chapters represent a spectrum of traditions, architectural styles, and historical contexts. Some are world-famous icons; others are hidden marvels. All are bound by their powerful ability to inspire wonder, reflection, and a sense of shared humanity across distances of both geography and time.

As you embark on this journey through The World’s Greatest Churches, may you find new appreciation for these masterpieces—not only as monuments of faith, but as living repositories of art, history, and the transcendent dreams of generations past and present.

There are buildings that command attention, and then there is Hagia Sophia. For nearly fifteen centuries, this colossal structure has dominated the skyline of Istanbul, a silent, stone sentinel witnessing the rise and fall of empires, the ebb and flow of cultures, and the passionate prayers of diverse faiths. Its name, "Holy Wisdom" in Greek (Ἁγία Σοφία), hints at the profound ambition behind its creation – not merely a place of worship, but an earthly reflection of the divine, a building designed to stretch the very limits of human ingenuity and artistic expression. To stand beneath its legendary dome is to feel the weight of history, the echo of ancient chants, and an undeniable sense of awe that transcends time and belief.

Anchored on the historic peninsula where Europe and Asia gaze at each other across the shimmering waters of the Bosphorus, Hagia Sophia is more than just an architectural masterpiece; it is a confluence of civilizations. Its story is Istanbul's story – a narrative of transformation, resilience, and enduring spiritual significance. It has been the jewel of Eastern Orthodox Christianity, the principal imperial mosque of the Ottoman Empire, a secular museum welcoming the world, and, in a recent turn, a mosque once more. Each layer of its history has left an indelible mark, making it one of the most complex and compelling sacred sites on Earth.

The Hagia Sophia we see today is not the first church to have graced this prominent spot. The original, known as the "Magna Ecclesia" or Great Church, was consecrated in 360 AD during the reign of Constantius II, son of Constantine the Great. This wooden-roofed basilica, like many grand ambitions of its time, proved vulnerable to the volatile politics of Constantinople. It was torched during riots in 404 AD. A second basilica, larger and more robust, was commissioned by Emperor Theodosius II and inaugurated in 415 AD. This, too, would meet a fiery end. The spark this time was not just any civic unrest, but the infamous Nika Riots of 532 AD.

These riots, fueled by fierce chariot-racing factions (the Blues and the Greens) and simmering discontent against Emperor Justinian I, engulfed the city in a week of unprecedented destruction. When the smoke cleared, much of Constantinople, including Theodosius' Hagia Sophia, lay in ruins. Justinian, having brutally suppressed the revolt, saw in the devastation not just a crisis, but an opportunity – a chance to rebuild the Great Church on a scale and with a splendor never before witnessed, a statement of his power and piety that would resonate through the ages. He vowed to create a monument so magnificent it would eclipse even Solomon's Temple in Jerusalem.

To realize this audacious vision, Justinian cast aside traditional master builders and instead turned to two brilliant Greek scholars, Anthemius of Tralles, a physicist and expert in geometry, and Isidorus of Miletus, a renowned mathematician and professor of stereometry. They were not merely architects in the conventional sense; they were theoreticians, visionaries who approached the project as a monumental problem in applied mechanics and optics. Their task was to erect a building that would redefine the possibilities of sacred space, crowned by a dome vaster than any previously attempted.

The speed with which they worked is nothing short of miraculous. Construction began a mere forty days after the Nika Riots subsided, in February 532, and the new Hagia Sophia was consecrated on December 27, 537 – just under six years. Ten thousand workers reportedly toiled day and night. Justinian, sparing no expense, commanded that the finest materials be brought from every corner of his vast empire. Enormous porphyry columns were shipped from Egypt, green marble from Thessaly, black stone from the Bosphorus region, and yellow stone from Syria. Ancient temples across the Mediterranean were plundered for their choicest elements, re-consecrating pagan spoils for Christian glory. Legend has it that upon entering the completed basilica for the first time, Justinian, overcome with emotion, exclaimed, "Solomon, I have surpassed thee!"

The centerpiece of Hagia Sophia, its defining glory, is undoubtedly its colossal dome. Soaring 55.6 meters (182.5 feet) from floor level, with a diameter that spans over 31 meters (102 feet), it was an engineering marvel of its time. Anthemius and Isidorus achieved this by employing a revolutionary architectural technique: pendentives. These four massive, concave triangular segments of masonry allowed for the transition from the square base of the supporting piers to the circular rim of the dome, creating an illusion that the dome was almost floating, suspended from heaven by a golden chain, as the contemporary historian Procopius described it. This was a radical departure from the simpler drum-supported domes of Roman tradition.

The visual effect is breathtaking. Forty arched windows encircle the base of the dome, flooding the vast interior with ethereal light. This "circle of light" was a deliberate design choice, making the dome appear almost weightless and imbuing the space below with a mystical aura. The play of light was central to Byzantine theology, symbolizing the Logos, the divine wisdom of God. As the sun arcs across the sky, its rays pierce through the windows at ever-changing angles, illuminating the golden mosaics and polished marble in a dynamic, almost living display.

However, such groundbreaking ambition came with its share of challenges. The original dome, completed in 537, was shallower and exerted immense outward pressure on the supporting piers. This structural daring proved too much, and following a series of earthquakes, a large section of it collapsed in 558 AD. Isidorus the Younger, nephew of the original Isidorus, was tasked with the reconstruction. He rebuilt the dome with a higher profile, incorporating lighter materials and adding 40 ribs to reinforce it, giving it the form we see today. Even so, parts of the dome collapsed again in 989 and 1346, requiring further repairs and buttressing over the centuries to ensure its survival against the region's seismic activity.

Beyond the dome, the sheer scale of Hagia Sophia’s interior is overwhelming. The vast nave stretches before you, flanked by soaring arcades supported by monolithic marble columns with intricately carved capitals, each a unique masterpiece of Byzantine craftsmanship. The original plan featured an upper gallery, or matroneum, traditionally reserved for women, which wraps around three sides of the nave, offering stunning perspectives of the space below. The richness of the materials is everywhere apparent: walls are revetted with multi-coloured marble panels, arranged in symmetrical patterns that resemble flowing water or intricate tapestries, creating a sense of opulent grandeur.

For nearly a thousand years, Hagia Sophia served as the patriarchal cathedral of Constantinople, the spiritual heart of the Eastern Orthodox Church. It was the setting for imperial coronations, royal weddings, solemn religious councils, and magnificent liturgical ceremonies that were legendary throughout Christendom for their splendor and intricacy. Imagine the scene: the emperor and empress, clad in jewel-encrusted robes, processing down the central aisle; the patriarch, surrounded by scores of clergy, chanting ancient hymns; the air thick with incense, the flickering light of countless candles reflecting off the golden mosaics and polished marble. It was in this very church, in 1054, that Cardinal Humbert, legate of Pope Leo IX, strode to the altar and placed a bull of excommunication upon it, marking a key moment in the Great Schism that formally divided Western and Eastern Christianity.

The artistic treasures of Hagia Sophia, particularly its mosaics, are among the most significant surviving examples of Byzantine art. Though many were plastered over or destroyed during periods of iconoclasm and later after the Ottoman conquest, those that remain offer a tantalizing glimpse into the building's original decorative scheme. The golden tesserae, angled to catch the light, create shimmering, ethereal images that seem to float against their luminous backgrounds.

Among the most famous mosaics is the stunning Deesis panel in the south gallery, dating from the late 13th century. It depicts Christ Pantocrator flanked by the Virgin Mary and John the Baptist, their faces rendered with remarkable psychological depth and compassion – a masterpiece of the Palaeologan Renaissance. Nearby, imperial portraits testify to the church's close ties with the Byzantine rulers. One shows Emperor Constantine IX Monomachos and Empress Zoe offering donations to a seated Christ; another portrays Emperor John II Komnenos and Empress Irene with the Virgin and Child. High in the apse, a majestic mosaic of the Theotokos (Virgin Mary) and Child, dating to the 9th century, gazes serenely down upon the faithful, one of the first figural mosaics reinstalled after the end of Byzantine Iconoclasm.

The serene grandeur of Hagia Sophia was dramatically shattered in 1204 with the arrival of the Fourth Crusade. Diverted from their original goal in the Holy Land, the Crusaders instead turned their forces on Christian Constantinople. The city was brutally sacked, and Hagia Sophia was desecrated and looted. Priceless relics, gold and silver altar furnishings, silk tapestries, and illuminated manuscripts were plundered and carted off to Western Europe. For nearly six decades, from 1204 to 1261, Hagia Sophia was converted into a Roman Catholic cathedral, a painful interlude in its long Orthodox history. The scars of this event ran deep, forever embittering relations between Eastern and Western Christianity.

The Byzantine Empire, though restored in 1261, never fully recovered its former strength or wealth. Hagia Sophia, while still revered, suffered from neglect and the empire's declining fortunes. The final, decisive chapter in its Byzantine story came on May 29, 1453. After a grueling fifty-three-day siege, the Ottoman forces, led by the young Sultan Mehmed II, breached Constantinople's legendary Theodosian Walls. The city fell, and with it, the Byzantine Empire came to an end after more than eleven centuries.

According to tradition, Sultan Mehmed rode directly to Hagia Sophia. Dismounting, he stooped to gather a handful of earth, which he sprinkled over his turban as an act of humility before God. He then entered the great church, amazed by its beauty and scale. Thousands of city residents had sought refuge within its walls, hoping for a divine miracle. The Sultan ordered the building to be immediately converted into a mosque. The last Christian liturgy had been held just hours before. That very Friday, the first Islamic prayers were recited within its hallowed space, and Hagia Sophia, the Great Church, became Ayasofya Camii, the principal imperial mosque of the Ottoman sultans.

The transformation from church to mosque involved significant architectural modifications, yet the Ottomans, for the most part, respected the essential structure of the building. A mihrab (a niche indicating the direction of Mecca) was installed in the apse, slightly off-center to align with the qibla. A minbar (pulpit) was added for the Friday sermon. Perhaps most visibly, four towering minarets were gradually erected around the edifice by successive sultans, forever altering its distinctive silhouette and firmly anchoring it within the Islamic architectural vernacular.

Inside, the magnificent Christian mosaics were not systematically destroyed, as was often the case in other converted churches. Instead, they were largely covered with plaster or whitewash in accordance with Islamic proscriptions against figural imagery in places of worship. Large calligraphic roundels, bearing the names of Allah, the Prophet Muhammad, the first four caliphs, and Muhammad's two grandsons, Hasan and Husayn, were installed on the main piers and in the apse. These impressive discs, crafted by the renowned 19th-century calligrapher Kazasker Mustafa İzzet Efendi, remain prominent features of the interior today.

For nearly five hundred years, Ayasofya served as the grand mosque of the Ottoman capital. It was a model and inspiration for countless other Ottoman mosques, including the nearby Sultan Ahmed Mosque (the Blue Mosque), whose architects consciously sought to emulate and even surpass Hagia Sophia's grandeur. Ottoman sultans lavished attention on the building, undertaking numerous restorations and additions, including the construction of an ablution fountain, a primary school, a library, and mausoleums for several sultans and their families within the complex. The great Ottoman architect Mimar Sinan, in the 16th century, undertook significant structural reinforcements, adding exterior buttresses that have helped the venerable building withstand centuries of earthquakes.

The next major transformation in Hagia Sophia's long and storied existence came in the early 20th century, following the collapse of the Ottoman Empire and the birth of the Turkish Republic under Mustafa Kemal Atatürk. In 1935, as part of Atatürk's sweeping secularization reforms, the Turkish government decreed that Hagia Sophia would cease to function as a mosque and would instead be converted into a museum. This decision was monumental. It allowed for the systematic uncovering and restoration of the long-hidden Byzantine mosaics, undertaken by teams of international experts, most notably Thomas Whittemore of the Byzantine Institute of America.

As a museum, Hagia Sophia became one of the most visited monuments in Turkey, drawing millions of tourists and scholars from around the globe each year. It stood as a powerful symbol of Istanbul's unique multicultural heritage, a place where Christian and Islamic elements coexisted, telling a story of converging civilizations. Its designation as part of the "Historic Areas of Istanbul" on the UNESCO World Heritage List in 1985 further cemented its status as a treasure of universal value. The careful work of conservators revealed more and more of its artistic splendors, allowing visitors to appreciate the layers of history embedded within its walls.

This museum status, however, remained a subject of debate. For decades, religious and nationalist groups in Turkey advocated for Hagia Sophia's reconversion to a mosque. These calls gained momentum in the early 21st century. In July 2020, after a Turkish court annulled the 1934 cabinet decree that had established it as a museum, President Recep Tayyip Erdoğan signed a new decree formally reclassifying Hagia Sophia as a mosque. The first Friday prayers in 86 years were held later that month, marking another significant turning point in the building’s narrative.

The decision sparked a range of reactions both within Turkey and internationally, with concerns raised by some about the future preservation of its Christian heritage and its continued accessibility to non-Muslim visitors. Turkish authorities have stated that Hagia Sophia will remain open to visitors outside of prayer times, and that its Christian iconography, while covered during Islamic worship, will not be permanently damaged. The long-term implications of this latest transformation are still unfolding, adding yet another complex layer to the building’s identity.

What, then, makes Hagia Sophia one of the "world's greatest churches," despite its centuries as a mosque and its more recent incarnation? It is precisely this layered history, this extraordinary capacity to adapt and endure, that contributes to its greatness. It is a building that has refused to be static, a canvas upon which successive empires and faiths have inscribed their highest aspirations. Its architectural audacity, particularly the ethereal dome that defied gravity and convention, set a new standard for sacred space and influenced countless buildings across disparate cultures for centuries to come.

The genius of Anthemius and Isidorus gave the world a structure where engineering and art merged seamlessly, where light itself became a building material, and where the sheer scale of the interior was designed to humble and uplift the human spirit. The remnants of its mosaics whisper tales of imperial power and profound piety, surviving iconoclasm, conquest, and the passage of time to testify to Byzantine artistic brilliance. Even its Ottoman additions, far from defacing it, added new dimensions of beauty and spiritual purpose, creating a unique hybrid that speaks to Istanbul's soul.

Hagia Sophia is not merely a monument to a single faith or a bygone era. It is a testament to the enduring human quest for connection with the divine, expressed through architectural innovation and artistic devotion. It embodies the grandeur of Byzantium, the might of the Ottomans, and the complex identity of modern Turkey. To walk through its vast, resonant space is to walk through history itself, to feel the echoes of emperors and sultans, patriarchs and imams, artisans and worshippers who, over fifteen hundred years, have all been touched by the profound and enduring mystery of Holy Wisdom.