Derbent occupies the narrow gateway between the Caspian Sea and the Caucasus Mountains connecting the Eurasian Steppe to the north and the Iranian Plateau to the south; covering an area of 69.63 square kilometres (26.88 sq mi), with a population of roughly 120,000 residents.

[8] Due to its strategic location, over the course of history, the city changed ownership many times, particularly among the Persian, Arab, Mongol, Timurid, and Shirvan kingdoms.

The Persian name for the city came into use at the end of the 5th or the beginning of the 6th century AD, when the city was re-established by Kavadh I of the Sassanid dynasty of Persia, but Derbent was probably already in the Sasanian sphere of influence as a result of the victory over the Parthians and the conquest of Caucasian Albania by Shapur I, the second shah of the Sassanid Persians.

Historically, this position allowed the rulers of Derbent to control land traffic between the Eurasian Steppe and the Middle East.

Until the 4th century AD, it was part of Caucasian Albania which was a satrapy of the Achaemenid Persian Empire, and is traditionally identified with Albana, the capital.

[11] The modern name is a Persian word (دربند Darband) meaning "gateway", which came into use in the end of the 5th or the beginning of the 6th century AD, when the city was re-established by Kavadh I of the Sassanid dynasty of Persia,[19] however, Derbent was probably already into the Sasanian sphere of influence as a result of the victory over the Parthians and the conquest of Caucasian Albania by Shapur I, the second shah of the Sassanid Persians.

[11] The 20-meter-high (66 ft) walls with thirty north-looking towers are believed to belong to the time of Kavadh's son, Khosrau I, who also directed the construction of Derbent's fortress.

During periods when the Sasanians were distracted by war with the Byzantines or protracted battles with the Hephthalites in the eastern provinces, the northern tribes succeeded in advancing into the Caucasus.

The first Sasanian attempt to seal off the road along the Caspian seacoast at Darband by means of a mud-brick wall has been dated in the reign of Yazdegerd II (438–457 AD).

[11] Movses Kagankatvatsi left a graphic description of the sack of Derbent by the hordes of Tong Yabghu of the Western Turkic Khaganate in 627.

His successor,[citation needed] As mentioned by the Encyclopedia Iranica, ancient Iranian language elements were absorbed into the everyday speech of the population of Dagestan and Derbent especially during the Sassanian era, and many remain current.

[22] In fact, a deliberate policy of “Persianizing” Derbent and the eastern Caucasus, in general, can be traced over many centuries, from Khosrow I to the Safavid shahs Ismail I, and ʿAbbās the Great.

The impression of antiquity evoked by these fortifications led many Arab historians to connect them with Khosrow I and to include them among the seven wonders of the world.

[11] The Darband fortress was certainly the most prominent Sasanian defensive construction in the Caucasus and could have been erected only by an extremely powerful central government.

The Caliph Harun al-Rashid lived in Derbent and brought it into great repute as a seat of the arts and commerce.

Derbent stayed under Iranian rule, while occasionally briefly taken by the Ottoman Turks such as in 1583 after the Battle of Torches and the Treaty of Constantinople, till the course of the 19th century, when the Russians occupied the city and wider Iranian-ruled swaths of Dagestan.

As a consequence of the Russo-Persian War (1804-1813) and the resulting Treaty of Gulistan of 1813, Derbent and wider Dagestan were ceded by Qajar Iran to the Russian Empire.

In the 1886 census of Dagestan Oblast, as part of Russia's Caucasus Viceroyalty, people of Iranian descent (Russian: персы) were still an absolute majority at 8,994 out of 15,265, or 58,9%.

[40] According to the 2021 Census, the main ethnic groups in the city are:[41] Jews began to settle in Derbent in ancient times.

[44] The chief rabbi of Derbent, Obadiah Isakov, was badly injured in an assassination attempt on July 25, 2013, sparking concerns of further acts of antisemitism targeting the Jewish community.

[46] In the 2024 Dagestan attacks, a synagogue in Derbent was set on fire by armed gunmen, possibly affiliated with ISIS.

[47][48] The city is home to machine building, food, textile, fishing, and fishery supplies, construction materials, and wood industries.

Derbent resembles a huge museum and has magnificent mountains and shore nearby, and therefore possesses much touristic potential, further increased by UNESCO's classification of the citadel, ancient city and fortress as a World Heritage Site in 2003; however, instability in the region has halted development.

The current fortification and walls were built by the Persian Sassanian Empire as a defensive structure against hostile nomadic people in the north, and continuously repaired or improved by later Arab, Mongol, Timurid, Shirvan, and Iranian kingdoms until the early course of the 19th century, as long as its military function lasted.