The city was founded by a decree of Emperor Nicholas I on June 12, 1844, according to which the Petrovskoye fortification was established. It was named in memory of Peter I’s stay in this area in 1722. By the end of 1851, by order of the governor and the Main Post Office, a post office was opened in the Petrovskoye fortification. From April 1, 1852, the lighthouse began operating from dusk till dawn, and five years later, the Caucasian governor conceived the idea of building a city: “With the aim of encouraging trade and industry along the northwestern shore of the Caspian Sea and attracting more settlers to this point, I find it useful to establish a port city near the aforementioned fortress, granting it the same rights as those enjoyed by Anapa, Novorossiysk, and Sukhumi-Kale, in accordance with local conditions…”
The governor’s proposal was accepted in St. Petersburg, and on October 24, 1857, an Imperial decree was sent to the Governing Senate stating: “…on the northwestern shore of the Caspian Sea, to establish a port city of Petrovsk near the Petrovskoye fortress and to grant certain privileges and benefits to individuals wishing to settle there.”
On May 28, 1858, Tsar Alexander II ordered the construction of a pier in the city, allocating 50,000 rubles for its construction. By the fall of the following year, rails, wagons, a locomotive, and other necessary equipment for building the pier were purchased in England with these funds. All the work was supervised by Lieutenant Colonel Falkenhagen.
Drinking water was supplied to the city through cast iron pipes from springs on Tarkinskaya Mountain to a large reservoir located at the highest point of the city, and from there, it was distributed via the same cast iron pipes to two water distribution basins.
In 1874, a rotunda was built in the Petrovsk city garden for dance evenings and other public entertainments, funded by members of the social club. By the 1880s, the city’s first printing press began operating.
In 1894, work began on the construction of the Petrovsk-Baku branch of the Rostov-Vladikavkaz railway. The first through train to Derbent passed this section on October 25, 1899, and regular traffic was opened on April 1, 1900.
On October 18, 1918, after the city was captured by the Whites, an attempt was made to rename Port-Petrovsk to Shamilkala, but after the establishment of Soviet power, the city regained its former name.
On February 26, 1923, the city became the capital of the Dagestan Autonomous Soviet Socialist Republic.