The Kaliakra Fortress is located on Cape Kaliakra on the Black Sea coast in Northeast Bulgaria (the region known as Dobrudzha). Cape Kaliakra is a 2 km long narrow headland towering about 70 meters above the sea level. The Kaliakra Fortress is part of the Kaliakra Archaeological Preserve, whereas the cape, the coast, and their hinterland are a nature preserve, home to rare birds and fish. It is located in Kavarna Municipality, near the towns of Kavarna, Balgarevo, and Sveti Nikola (St. Nicholas).
The earliest traces of human settlement on the territory of Cape Kaliakra and the Kaliakra Fortress date back to the 4th century BC when the region was inhabited by the Ancient Thracian tribe Tirizi or Tirici, a subgroup of the Getae (Gets); respectively, the earliest known name of the settlement was Tirizis (Tirissa in Latin). The name “Kaliakra" is believed to come from the Byzantine period and is translated from Greek as meaning “beautiful headland" (or “beautiful fortress").
Ancient Greek geographer Strabo (64 BC – ca. 24 AD) wrote that Kaliakra was the capital of Lysimachus (r. 306-281 BC), one of Alexander I the Great’s generals, and one of his diadochi (successors) who became King of Macedon, Thrace, and Asia Minor, and used the caves of Cape Kaliakra to hide treasures that he amassed during the campaigns against Persia.
The first fortifications on Cape Kaliakra were built by the Ancient Thracians, with a second fortress wall added during the Hellenistic Period (3rd-1st century BC). Another expansion of the Kaliakra Fortress was made during the Roman Period. By the middle of the 4th century AD, the fortress already had an inner and outer city, with round fortress towers built in 341-342 AD. A third and stiller outer fortress wall was built in the second half of the 4th century AD. It was 10 meters tall about almost 3 meters wide.
According to 6th century AD Byzantine geographer Hierocles (author of the Synecdemus), in the 5th-6th century, the Kaliakra Fortress was a major stronghold of the Byzantine (Eastern Roman) Empire against the barbarian peoples invading from the north.
In 513 AD, Kaliakra was the site of a battle between the forces of Byzantine general Vitalian (d. 520), a native of the city of Zaldapa (in today’s Krushari Municipality in Northeast Bulgaria) and Byzantine Emperor Anastasius I Dicorus (r. 491-518 AD). Vitalian’s rebellion grew into a 5-year civil war.
At the end of the 7th century, the region of the Kaliakra Fortress was conquered by the First Bulgarian Empire (632/680-1018 AD). Sources from the 10th century mention the fortress with the Slavic name Tetrasida.
The earliest Western European source to mention the Kaliakra Fortress is a map by Italian cartographer Petrus Visconte from 1318 AD. The city of the Kaliakra Fortress saw its height in the second half of the 14th century, the same period that saw the demise of the Second Bulgarian Empire (1185-1396)
Bulgarian Tsar Ivan Alexander (r. 1331-1371 AD) lost his two eldest sons (Ivan in 1349 AD and Mihail in 1355 AD) in battles with the Ottoman Turks, failed to prevent a number of Bulgarian feudal lords from seceding, and on top of that divided the remainder of the Second Bulgarian Empire between his two surviving sons.
His third son Ivan Sratsimir (r. 1371-1396) received the smaller so called Vidin Tsardom, with the Danube city of Bdin (Vidin) as its capital, and his fourth son Ivan Shishman (r. 1371-1395) received the rest, the so called Tarnovo Tsardom, with the capital proper of Tarnovgrad (today’s Veliko Tarnovo).
Bulgarian boyar Balik (r. ca. 1337-1366 AD), a powerful feudal lord, acquired independence from the Bulgarian Tsars setting up the so called Dobrudzha Despotate, also known as the Principality of Karvuna, in the region of Dobrudzha, today’s Northeast Bulgaria and Southeast Romania, which included the city and fortress of Kaliakra. He was succeeded by his co-ruler and brother, Despot Dobrotitsa (r. 1347-1385 AD).
The Dobrudzha Despotate itself was destroyed by the Ottoman Turks in 1388 AD. The name of the region of Dobrudzha is believed to have stemmed from the Turkish pronunciation of the name of Despot Debrotitsa.
The Despots of the Principality of Karvuna were the first Bulgarian rulers to build a major (Black Sea) navy.
Wallachian Voivode Mircea the Elder, whose documents were written in Bulgarian, in the Bulgaric (Cyrillic) alphabet, was first an ally of the Bulgarian Tsar Ivan Shishman, with whose aid he even came to control briefly parts of the Dobrudzha Despotate, styling himself “master of Silistra and the lands of Despot Dobrotitsa" in 1390-1391. He regained the region around Kaliakra in 1402 but lost it again to the Ottoman Turks in 1403.
In 1444, the crusaders of Vladislav (Wladyslaw) III Jagello, also known as Varnenchik, King of Poland and Hungary, camped near the Kaliakra Fortress during his second campaigns against the Ottoman Empire (a few decades after it had conquered the Second Bulgarian Empire), shortly before the Battle of Varna.
The Kaliakra Fortress and Cape Kaliakra are also known as the site of the largest naval battle to ever take place in the Black Sea – the Battle of Cape Kaliakra in the summer of 1791. It was the last naval battle of the Russian-Turkish War of 1787-1792, in which the Russian Navy under Admiral Fyodor Ushakov won a victory against the Ottoman Navy led by Hussein Pasha.
During the period of the Ottoman Empire, a place at the Kaliakra Cape connected with the legend of St. Nicholas (see below) is believed to have been the site of a dervish monastery keeping the relics of Muslim Bektashi Saint Sari Saltik.
The first modern lighthouse on Cape Kaliakra was built in 1866 by the Compagnie des Phares de l’Empire Ottomane; the present lighthouse was erected in 1901, during the period of the Third Bulgarian Tsardom (1878-1946).
Cape Kaliakra and the fortress are connected with a lot of legends. The most famous is the one about the 40 Bulgarian maidens who tied their hair together, and committed suicide by jumping into the Black Sea off the 70-meter-tall cliffs in order to avoid being captured and raped by the Ottomans. An obelisk called “The Gate of the Forty Maidens" has been erected at the entrance of the cape in dedication of this legend.
According to another major legend, Cape Kaliakra was created by God in order to rescue St. Nicholas from the Ottomans by extending the ground under his feet while he was running from them. He was eventually caught, and a chapel exists today on the alleged spot of his capture.
A third major legend about Kaliakra has it that Lysimachus perished there with his entire fleet, having escaped there with the treasure of Alexander the Great.
The archaeological excavations on Cape Kaliakra have also revealed ancient and Early Christian necropolises.
The Late Antiquity fortress on Cape Kaliakra had a territory of about 250 decares (app. 62 acres). The third and outermost fortress wall is 1.25 km away from the end of the cape, and is 422 meters long; it had 5 fortress towers. The middle fortress wall is located 400 meters away, and is 162 meters long, and also had a moat. The innermost fortress wall is located 325 meters away from the middle wall, and is 30 meters long.