Built between 548 and 565 CE, the monastery is one of the oldest working Christian monasteries in the world. The oldest record of monastic life at Sinai comes from the travel journal written in Latin by a woman named Egeria about 381–384 CE. The site is sacred to Christianity, Islam, and Judaism. The living bush on the grounds is purportedly the one seen by Moses.

circa 381 CE- Present

Early Monastic Presence at Mount Sinai
The earliest known record of monastic life at Mount Sinai comes from the Latin travel journal of Egeria (also known as Etheria or Saint Sylvia of Aquitaine), a Christian pilgrim who visited the region between 381 and 386 CE. Her account describes the spiritual significance of the area and the presence of ascetic Christian monks living in isolation near the site traditionally associated with Moses' encounter with the burning bush.

Construction Under Emperor Justinian I
The Monastery of Saint Catherine was commissioned by Emperor Justinian I, who reigned from 527 to 565 CE, to enclose the earlier Chapel of the Burning Bush. This chapel, also known as "Saint Helen's Chapel," was originally built by Empress Helena, the mother of Constantine the Great, at the site where Moses is traditionally believed to have seen the burning bush. The monastery's most remarkable architectural feature is its king post truss, which remains the oldest known surviving roof truss in the world. The bush growing within the monastery’s walls is believed by the monastic community to be the very same one described in biblical tradition.

Early Muslim Period
The seventh century saw the destruction of some of the isolated Christian anchorite settlements in the Sinai, leaving the fortified monastery as the last remaining Christian stronghold in the region. Its massive defensive walls, constructed under Justinian I, may have played a crucial role in its survival. Until the early 20th century, access to the monastery was only possible through a door high in the outer walls, emphasizing its defensive nature.

Fatimid Period
During the Fatimid Caliphate (909–1171 CE), the monastery remain an active center of Christian monastic presence in the region. However, given the reverence of the site and its affiliation to Moses, a revered prophet in Islam and Christianity, an existing chapel within the monastery complex was converted into a mosque.

Mamluk Period
Under the Mamluk Sultanate, the monastery generally flourished. However, as the sultanate weakened in the late 15th century, it faced increasing threats. The number of monks declined from several hundred in the mid-14th century to only a few dozen a century later. Local Bedouin tribes began attacking the community, looting its property in the Christian coastal village of al-Tur. In 1505, the monastery itself was captured and plundered. Though the sultan ordered that the stolen property be returned, the Mamluk authorities were unable to control the Bedouin nomads or enforce stability. German explorer Martin Baumgarten, who visited in 1507, documented the monastery’s state of decline. During this period the mosque-chapel remained in regular use until the late Mamluk period in the late 15th to 16th century CE, after which it was used only on special occasions.

Crusader Period
Following the First Crusade (1096–1099), the presence of European Crusaders in the Sinai region stimulated Christian interest in the monastery, increasing the number of pilgrims from Europe. The monastery was sustained by its extensive network of dependencies in Egypt, Palestine, Syria, Crete, Cyprus, and Constantinople. Throughout the medieval period, its monastic community was multiethnic, comprising monks of Arab, Greek, Syrian, Slavonic, and Georgian backgrounds.

Ottoman Period
When the Ottoman Empire took control of Egypt in 1517, the Monastery of Saint Catherine came under Ottoman jurisdiction. Unlike the late Mamluk period, when the monastery suffered from Bedouin raids and a declining monastic population, the early Ottoman sultans provided renewed protection. The monastery maintained its privileged status, largely due to its religious significance and historical ties with both Eastern Orthodox and Islamic rulers.

Sultans such as Selim I (reigned 1512–1520) and Suleiman the Magnificent (reigned 1520–1566) reaffirmed the monastery’s rights, granting official decrees (firmans) that ensured its autonomy and safeguarded its properties. These firmans helped secure the monastery from Bedouin encroachments and allowed the monks to manage their dependencies in the wider region.

From the late 15th century onward, rulers of Wallachia (a principality in modern Romania) began offering financial support to the monastery. This patronage intensified during the Ottoman period, particularly in the 17th and 18th centuries, when Romanian princes sent generous donations, funded monastic renovations, and provided supplies.

By the 18th century, Russian Orthodox influence also grew. With the rise of Russia as a major Orthodox power, Russian pilgrims and imperial officials increasingly viewed Saint Catherine’s Monastery as a site of religious and cultural significance. While the monastery remained under Ottoman rule, Russian diplomatic influence sometimes acted as a protective force, ensuring its continued operation.

During the Middle Ages, the monastery had a diverse community of monks from Arab, Greek, Syrian, Slavonic, and Georgian backgrounds. However, by the Ottoman period, it became almost exclusively Greek. This shift may have been influenced by the depopulation of Christian communities in Transjordan and the broader region, as well as the dominance of the Greek Orthodox Church within Ottoman-controlled Christian institutions. The Archbishop of Sinai, who also served as the abbot of the monastery, was typically a Greek hierarch, and by the 18th century, most of the monks were of Greek origin.

While the monastery retained a degree of protection under Ottoman rule, the 19th century brought new challenges. The Ottoman Empire was weakening, and Bedouin groups in the Sinai region became more assertive. Pilgrims and monks often faced difficulties traveling between the monastery and its dependencies. Western travelers who visited during this period, including European scholars and explorers, noted that the monastic community had dwindled in numbers.

At the same time, Western interest in the monastery increased, particularly among British and German scholars who sought access to its ancient manuscripts. In 1859, German biblical scholar Constantin von Tischendorf famously discovered the Codex Sinaiticus, one of the oldest surviving complete manuscripts of the Bible. His removal of the codex, which he later presented to Tsar Alexander II of Russia, sparked controversy that continues to this day.

Modern Period
The Ottoman period came to an end in 1917 when British forces took control of Sinai during World War I. This marked the beginning of a new era for the monastery under British, and later Egyptian, administration. Despite political changes, the monastery remained an important center of Eastern Orthodox Christianity and continued to attract scholars and pilgrims from around the world.

circa 555 CE

Justinian Basilica
The Justinian Basilica, also known as the Church of the Transfiguration, is the central structure within Saint Catherine's Monastery at the foot of Mount Sinai. It was built by order of Emperor Justinian I (reigned 527–565 CE) as part of the monastery's fortification and expansion. The basilica was constructed to replace an earlier church, traditionally believed to have been commissioned by Empress Helena (circa 325 CE), the mother of Constantine the Great, at the site of the Burning Bush.

The church follows a Byzantine basilica design, featuring a three-aisled nave, a large apse, and a series of granite columns. Its walls are adorned with some of the finest surviving early Christian mosaics, including the famous apse mosaic of the Transfiguration, which depicts Christ in radiant light, surrounded by Moses, Elijah, and the Apostles Peter, James, and John. This masterpiece, created with gold and glass tesserae, reflects the theological significance of Mount Sinai as a place of divine revelation. The basilica also houses an elaborate iconostasis, added in later centuries, and a collection of icons and manuscripts, many of which belong to the monastery’s renowned library, one of the oldest in the Christian world.

Despite centuries of political and religious changes, the Justinian Basilica has remained remarkably intact, continuing to serve as the heart of Orthodox monastic life at Saint Catherine’s Monastery. It remains a site of pilgrimage and worship, preserving its status as one of the most significant early Byzantine churches still in use today.

circa 555 CE

The Burning Bush
The so-called burning bush, also known as the living bush, within the grounds of Saint Catherine's Monastery is traditionally revered as the very bush from which God spoke to Moses, as described in the Book of Exodus. According to biblical tradition, while tending the flock of his father-in-law Jethro, Moses encountered a bush that was engulfed in flames yet remained unconsumed. From within the fire, God commanded him to lead the Israelites out of Egypt, marking a pivotal moment in Jewish, Christian, and Islamic tradition. The event is central to Abrahamic religious narratives, symbolizing divine revelation, sacred presence, and the commissioning of a prophet. In Christian thought, the Burning Bush is also interpreted as a prefiguration of the Virgin Mary, who bore the divine presence without being consumed.

The monastery, built by order of Emperor Justinian I (reigned 527–565), was constructed to enclose the sacred site, ensuring its preservation as a place of veneration. Within the complex, the Chapel of the Burning Bush, also known as Saint Helen’s Chapel, was originally commissioned by Empress Helena, the mother of Constantine the Great, during her extensive efforts to identify and mark Christian holy sites. The bush itself, identified as a species of Rubus sanctus (a type of bramble), continues to grow within the monastery’s walls. Over centuries, countless pilgrims and monastic communities have honored this sacred relic, further solidifying its place as a spiritual landmark at the foot of Mount Sinai, where tradition holds that Moses later received the Tablets of the Law.

circa 555 CE

Library
Archives of Library of Saint Catherine's Monastery is the world's oldest continually operating library, possessing many unique books including the Syriac Sinaiticus and, until 1859, the Codex Sinaiticus. The monastery library preserves the second largest collection of early codices and manuscripts in the world, outnumbered only by the Vatican Library. The library is believed to possess a document called the the Ahdname of Muhammad (Ashtiname of Muhammad), also known as the Covenant or Testament (Testamentum) of Muhammad, which is a charter or writ allegedly ratified by the prophet Muhammad granting protection to the followers of Jesus the Nazarene, at the Monastery.

circa 560 CE

Ossuary-Chapel and Skeleton of Stephanos the Monk
Within Saint Catherine’s Monastery at the base of Mount Sinai (Jabal Musa), there is a small but historically significant Ossuary-Chapel, which houses the remains of monks who lived and died in the monastery over the centuries. Given the monastery’s remote location and the limited space within its walls, a traditional burial ground was impractical. Instead, the remains of deceased monks were exhumed after a period of time and transferred to this ossuary, following a long-standing monastic tradition observed in many Orthodox Christian monasteries.

One of the most notable relics within the ossuary is the skeleton of Stephanos the Monk, a monastic figure believed to have lived at the monastery in the past. His remains, like those of other monks, were preserved in the ossuary as a mark of reverence and remembrance. The bones of the monks are carefully arranged within the chapel, with skulls and skeletal remains placed in an orderly manner. This practice reflects the Orthodox Christian belief in humility and the transient nature of life, emphasizing the monks’ dedication to spiritual pursuits over worldly concerns.

The Ossuary-Chapel remains an important site within the monastery complex, offering visitors and pilgrims a glimpse into the monastic life and death rituals followed by the community for centuries. It serves as a solemn reminder of the monks' devotion and the monastery’s unbroken history as a center of Christian faith in the Sinai Peninsula.

circa 560 CE

Chapel of Saint Tryphon
It is a small chapel called the Chapel of St. Tryphon which serves as an ossuary for the skulls of deceased monastics. Differing from many ossuaries and charnels, St. Catherine’s was based more on functionality than decoration, and the massive pile of remains speaks to that gruesome end. The most important relic in the cathedral is the remains of St. Tryphon, which rest in the chapel, garbbed in black.

circa 910 CE

Mosque
The mosque is located north-west of the the Justinian period basilica. Originally it had served as the monastery refectory (from the 6th century CE) until the the 11th or 12th century CE. It is a small somewhat square structure with a minaret on the south-east corner. The minaret, situated directly facing the belfry of the basilica, is of square constrcution topped by a small dome. It is composed of three parts, with access between the three areas by means of large arched openings.