Announcing the major find on Thursday, the emirate’s tourism and archaeology department said the complex included a church, refectory (dining hall), cisterns and cells for the monks where they spent time in solitude.
Radiocarbon dating and assessment of pottery excavated at the site suggests the community flourished there between the late sixth century up to the middle of the eighth century, meaning it could have been established in the pre-Islamic era.
The find also sheds light on a time when Christianity and Islam coexisted and reveals more about the Christian Arab population that went on to thrive in East Arabia.
Al Sinniyah, shaped like several fingers, is located between the Umm Al Quwain peninsula and the Gulf coast and it protects the mangrove-fringed Khor Al Beida lagoon.
All around its shores is evidence of human occupation that spans thousands of years.
It is the second monastery found in the UAE after the discovery of one on Abu Dhabi’s Sir Bani Yas Island in the early 1990s.
Six ancient monasteries have so far been found along the shores of the Arabian Gulf.
“It is an extremely rare discovery,” said Prof Tim Power of the UAE University, who was part of the team that unearthed the monastery. “It is an important reminder of a lost chapter of Arab history.”
The find was made under the Sinniyah Archaeology Project, a collaboration between the Umm Al Quwain Department of Tourism and Archaeology, the Institute for the Study of the Ancient World at New York University in New York and the Italian Archaeological Mission in Umm Al Quwain.
It is further supported by the UAE Ministry of Culture and Youth.
Noura Al Kaabi, Minister of Culture and Youth, Zaki Nusseibeh, Cultural Adviser to the UAE President and Chancellor of UAE University, and Sheikh Majid Al Mualla, chairman of the Umm Al Quwain's tourism and archaeology department, attended the event at the site on Thursday.
“The UAE government is making great efforts to protect and preserve the local heritage for generations to come in continuation of the approach adopted by the late Founding Father Sheikh Zayed bin Sultan Al Nahyan,” said Ms Al Kaabi.
“This is what urges us to continue our commitment to protecting our heritage and history, of which we are proud.”
The discovery of the monastery was first made last year and further reinforces Al Sinniyah as one of the most important archaeological sites in the UAE.
Today the ruins are in an area remote and uninhabited. However, more than a thousand years ago people lived, traded and prayed on the island.
The monastery encompassed a cluster of buildings including a kitchen, storerooms and cistern for collecting drinking water and an oven for communion bread. Adjacent is an abbot’s house or “bishop’s palace”.
The monastery was built of local beach rock and the walls and floors were covered with a type of lime plaster.
A large cistern found close to the altar could have potentially been used for baptisms. It is believed they celebrated mass at the single-aisle church, prayed seven times a day, chanted prayers and even sang hymns.
Archaeologists unearthed an altar and bowls that are thought to have been used for mixing wine.
“We also found oversized glass chalices,” said Prof Power. “They are not the sort to drink from and were intended to deliver the Eucharist and for the ceremony.”
Prof Power said monks of this region were famous for ascetic practices and could be compared to the monastic community that existed on Iona on the west coast of Scotland from the sixth century.
Archaeologists said it was important to note it was not built by visitors. It is considered an Arab Christian building that was not alien and is very much part of a local story.
After the rise of Islam, Prof Power said there was a period of about 300 years where the two religions coexisted.
“A narrative of violent conquest doesn’t work,” he said. “The place was slowly abandoned. There was no sign of devastation or violence or burning. There was incremental cultural and social change as Christianity faded out and Islam became dominant. It is a monument to tolerance and multi-faith society.”
“Islam is not the first monotheistic community to arrive but it paves the way for the spread of Islam. The fact there was a Christian Arab population in East Arabia has kind of been overlooked. So, this discovery is an important reminder of a lost chapter of Arab history.”
Earlier this year, digs on the island proved that the town of Umm Al Quwain was at least 700 years old.
Two settlements were uncovered, with the oldest believed to be from the 13th or 14th century.
Previously UAQ was thought to have grown up around the fort established by Sheikh Rashid bin Majid Al Mualla in 1768.
Further excavations of the monastery are planned at the site for next year.