The ruins of a small medieval monastery (in the top right corner) have been discovered, among Ancient Thracian, and Early Byzantine structures, on the tiny Black Sea island off Bulgaria’s coast. Photo: National Museum of History
An Ancient Thracian settlement, an Early Byzantine settlement, and a small monastery from the Late Middle Ages have been discovered by archaeologists on Bulgaria’s tiny St. Thomas Island (Snake Island) in the Black Sea.
The archaeological structures on the St. Thomas Island were discovered in June 2018 during the first phase of the island’s first ever archaeological research led by Prof. Ivan Hristov from Bulgaria’s National Museum of History in Sofia.
In the second phase of the research, in August 2018, Hristov’s team carried out an underwater archaeology expedition.
It has discovered a now sunken fortress from Ancient Thrace in the waters between the island and the Bulgarian mainland, or what used to be an isthmus, while the St. Thomas Island used to be a peninsula until the Middle Ages.
The archaeological remains which have now been discovered on the St. Thomas Island include the remains of an Ancient Thracian settlement from the Early Iron Age, Ancient Thracian ritual pits, and an Early Byzantine (/Late Roman) settlement from the 5th – 6th century AD, and a small monastery from the Middle Ages, more precisely, the 12th – 14th century, the time of the Second Bulgarian Empire (1185 – 1396/1422).
The St. Thomas Island is located north of the mouth of the Ropotamo River, in the Bay of Arkutino, and is actually part of the Ropotamo Natural Preserve. Photo: National Museum of History
St. Thomas Island (Snake Island) lies only 0.2 nautical miles (appr. 370 meters) from the Bulgarian mainland, off Primorko’s Blacks Sea coast. Photo: Sozopol Municipality
The archaeological exploration of the St. Thomas Island in the Black Sea has been carried out under the strict requirements of Bulgaria’s Ministry of Environment and Waters since the island is part of the Ropotamo Natural Preserve.
The exploration of the island itself and the underwater archaeology research in the Bay of Arkutino are funded by Bulgaria’s Ministry of Culture.
“About a century ago, the island was photographed from an airplane, and photos showed the outlines of the small monastery," diver Tencho Tenev, who has been in charge of the diving expedition, told Bulgaria on Air TV.
Bulgaria’s National Museum of History in Sofia hypothesizes that there probably are more Ancient Thracian ritual pits on the St. Thomas Island off the Black Sea coast of Bulgaria’s Primorsko, beyond the two that have now been discovered.
Fragments from ancient amphorae found in the pits indicate that they were used by the Ancient Thracians for sacrifice rituals starting in the 5th century BC
“The exposed finds indicate that a large sea route shrine was located on the St. Thomas Island," the Museum says, referring to what was a small Black Sea peninsula at the time.
“The place was chosen for a reason since it was right off the ancient road from Sozopol (Apollonia Pontica, Sozopolis) to Constantinople (at the time the Ancient Greek colony of Byzantium or Byzantion)," the Museum adds.
The newly unearthed ruins of a small monastery which existed in the 12th – 14th century on the St. Thomas Island. Photo: National Museum of History
The first and only previous archaeological expedition on Bulgaria’s St. Thomas Island in the Black Sea began in 1955.
Back then the archaeologists exposed the ruins of a small church and some auxiliary buildings. Now the 2018 archaeological expedition has built upon that research finding the ruins of what was a small medieval monastery.
The St. Thomas Island in the Black Sea has a total territory of 0.012 square kilometers (12 decares, or 3 acres).
It lies only 0.2 nautical miles (appr. 370 meters) from the mainland, and is located north of the mouth of the Ropotamo River, in the Bay of Arkutino, and is actually part of the Ropotamo Natural Preserve.
It also known as the Snake Island (not to be confused with the Ukrainian Snake Island (or Serpent Island) in the Northern Black Sea) because of the large number of grey water snakes that inhabit it.
Bulgaria has only several tiny islands off its coast in the Black Sea (six, seven, or eight depending on how the definition of an island, and whether islands now artificially connected to the mainland are counted.
Many of those were seemingly former peninsulas, and pretty much all of Bulgaria’s Black Sea coast boasts stunning underwater archaeology remains precisely thanks to the partial or full sinking of the coast in the Prehistory, Antiquity, and Middle Ages.
A 2,000-year-old sunken Ancient Roman ship was recently discovered on the bottom of the Black Sea in Bulgaria’s territorial waters by the international Black Sea M.A.P. expedition, alongside several dozen other ancient, medieval, and Modern Era shipwrecks.
The St. Thomas Island in the Black Sea has a total territory of 0.012 square kilometers (12 decares, or 3 acres). Photo: National Museum of History
The newly discovered Ancient Thracian sunken fortress at the St. Thomas Island adds another great underwater archaeology landmark to the Bulgarian Black Sea coast.
Prof. Ivan Hristov from Bulgaria’s National Museum of History in Sofia is a long-time researcher of the archaeological sites along Bulgaria’s Black Sea coast, including a number of fully or partly sunken settlements and fortresses.
He recently published a book based on 8 years of field research of fortresses and settlements on the southern Black Sea coast of today’s Bulgaria, or what once was Byzantium’s Haemimontus province.
The book is entitled “Mare Ponticum. Coastal Fortresses and Harbor Zones in the Province of Haemimontus, 5th – 7th Century AD", and looks at the Haemimontus province of the Early Byzantine Empire in the Late Antiquity and early Middle Ages.
Also check out these stories about sunken or submerged cities along Bulgaria’s Black Sea coast and beyond: