The history of the fort "Grand Duke Konstantin" begins in 1808 with the construction of an ancient stone two-tier battery for 45 guns. The need for construction was dictated by the defense of the borders against ships of the British fleet, which conducted military operations in the Baltic Sea, a decision made by the naval department of the Russian Empire. The battery was named "Double Southern." Its construction technology differed from the methods tested at that time. For example, the log structures were made on the shore and then towed to the construction site. In spring, wooden logs were installed on the shoal in the northern part of the Kronstadt roadstead and were covered with stone. On this foundation, which rose 1.5 meters above the ordinary level, the construction of the wooden battery began. The battery, named "Double Southern," was armed with twenty-five 36-pounder, twelve 30-pounder guns, and twelve unicorns. The garrison consisted of 250 personnel.

During the flood on November 6, 1824, the battery suffered less damage than other Kronstadt forts and was fully restored by spring 1826.

In 1834, to protect against possible attacks from the rear, a caponier (also on a filled wooden foundation) was built in the gorge, forming an inner harbor open on two sides. Around the battery, about 200 meters away, two rows of piles were driven into the bottom of the bay to prevent enemy ships from approaching. In the same year, Emperor Nicholas I, after visiting the battery, ordered it to be renamed Fort "Konstantin" in honor of his son, Grand Duke Konstantin Nikolaevich, who in 1831 at the age of 4 was appointed General-Admiral of the Russian fleet.

In the early 1850s, due to the deterioration of the wooden structures, it was decided to dismantle them. The work was completed by spring 1854. Due to the outbreak of the Crimean War, a temporary Battery No. 4 was built on the old raft foundation of Fort "Konstantin" and the Double Southern battery. After the war, the Naval Department decided to create a more powerful and modern fortification on the site of the temporary Battery No. 4 with a granite escarpment wall; this fortification was to provide protection against artillery fire and enemy landings. After the Crimean campaign, the future engineer-general of the Russian Imperial Army, Bergh, who had combat experience gained during the defense of the city, was called from Sevastopol to assist the builders.

In 1858, under the leadership of Engineer Major General I. G. Dzichkants (from 1860 — Engineer Colonel K. Ya. Zverev), construction of the escarpment wall of the new permanent Konstantin battery began in front of the existing temporary naval Battery No. 4. It was built from granite boulders weighing 10 tons each and faced with granite slabs weighing 6 tons each. The joints between the facing slabs were sealed with lead strips. The wall was brought up to 4 meters in height and up to 300 meters in length along the front. The wall was completed by summer 1860, and the overall construction of the permanent Konstantin battery island was completed in 1861. However, the construction of the battery itself was delayed. Combat-ready artillery positions on the permanent battery appeared only in the first half of 1863 during the urgent strengthening of the fortress amid worsening international tensions.

In October 1863, the Main Engineering Directorate demanded the protection of the fort's guns be reinforced with armored parapets (a world first). Between 1863 and 1865, the Konstantin battery and temporary Battery No. 4 were connected, and the left flank of the Konstantin battery was extended by 80 meters. New 8" Krupp guns were installed on the batteries. In 1866, a barracks for eight cubicles with a semi-basement was built on the right flank, protected by a two-meter-high stone wall and an earthen rampart. In 1868, a barracks was built in the middle part of the Konstantin battery.

In 1868, a decision was made to build a new 6-gun parapet. Initially, it was planned to be built according to the Lancaster system (from armored beams), but during construction, the design was changed, replacing the armored beams with plates. After construction, this parapet became known as Kolpinsky. Above the existing parapets, by order of General-Adjutant E. I. Totleben, iron bunkers covered with earth began to be built. However, construction was significantly delayed due to metal supply interruptions. Ultimately, only the 3-gun Lancaster parapet and the 6-gun committee system parapet were covered. On June 13, 1868, the "Konstantin" battery, together with the attached temporary Battery No. 4, was renamed Naval Southern Battery No. 4 "Konstantin" by decree of Emperor Alexander II.

Fort "Grand Duke Konstantin" is located in Kronstadt, a district of Saint Petersburg, situated on Kotlin Island, 48 km from the city. Fort "Konstantin" was built as an innovative project ahead of its time. Although its construction began in the early 19th century and, seemingly, over the years the site could have lost its significance, this did not prevent it from playing a significant role during the Great Patriotic War, as will be described in more detail below.

The buildings on the territory of Fort "Konstantin" underwent multiple reconstructions, but the atmosphere of that time remains untouched. This magnificent architectural monument, the cries of seagulls, the sound of the sea, and the fascinating stories of experienced guides invariably leave the most positive impressions of visiting the fort.

The special status of the structure was emphasized even during construction. The latest models of weapons and fire control devices were installed here. The modern name appeared somewhat later, in 1834, after the visit of Emperor Nicholas I, who ordered the battery to be renamed in honor of his son Konstantin. It was armed with guns, twenty-five of which were 36-pounders, and twelve were 30-pounders. Additionally, twelve unicorns—smoothbore artillery howitzers invented in 1757 by Russian artilleryman M. V. Danilov together with S. A. Martynov—were installed. The main purpose of the battery was direct fire against enemy ships. This type of fire was called "dagger fire." As for the "living force," i.e., the garrison of the tower, it included more than 250 thousand people.

In the 1850s, Fort "Konstantin" fell into disrepair, and a decision was made to reconstruct it. By 1858, granite fortifications began to be erected. The weight of the granite boulders, which were faced with slabs, was about 10 tons. The wall reached 4 meters in height and 300 meters in width. The construction of the barrier took 3 years and was completed in 1861. The granite facing completely solved the problem of wall wear resistance and eliminated the need for annual repairs.

Two years later, the Main Engineering Directorate demanded—for the first time in world practice—to strengthen the protection of Fort "Konstantin"'s guns with three armored parapets. Initially, three parapets were planned. The first, granite, was designed for 5 guns (the project was by Engineer Lieutenant Colonel Shvede), the second, made of armored plates mounted on triangular metal supports, was for 15 guns. Finally, the third, according to the so-called Lancaster system (made of 30 cm wooden beams), was for 3 guns.

There were also two other batteries protecting the rest of the fort's walls, but they have not survived either. The same applies to the second "dagger fire" battery. In 1870, the project of the famous Russian physicist Fyodor Fomich Petrushevsky, who invented a number of optical instruments, was implemented to build a pavilion for an optical rangefinder. This allowed full observation and fire control from the forts "Pavel I" and "Emperor Alexander I," better known by its second name—"Plague Fort."

In 1870, a special pavilion for the optical rangefinder was placed on the earthen traverse located between the 9- and 6-gun parapets, designed by Colonel V. F. Petrushevsky. The upper part of the pavilion rotated, providing the ability to survey the terrain over a wide sector. The pavilion was connected to the forts "Pavel I" and "Alexander I" via specially laid underwater cables, enabling concentrated fire from the forts on a target.

In the same year, casemates and wells for installing two "disappearing" guns of the Pauker system were built on the left flank of the battery—this mechanism allowed reducing the reload time of heavy guns from 5 minutes to 15 seconds. The lifting mechanisms, powered by steam, were refined for almost seven years.

In 1872, the fort was rearmed with 11" rifled guns, in 1873 supplemented with a 9" rifled mortar, and in 1878 with a 14" Krupp gun.

In 1890, a dam was built connecting the fort to Kotlin Island. A railway was laid on the dam.

On November 30, 1898, a bomb exploded during ammunition handling in one of the barracks casemates of the concrete 6-inch battery. Fourteen people died in the tragedy. They were buried in the Kronstadt cemetery, and the grave and tombstone have been preserved to this day.

In the summer of 1899, officers of the Mine Officer Class conducted experimental research on wireless telegraphy between the forts of Kotlin Island. During the experiments, the transmitting station was installed at Fort "Konstantin," and the receiving station at Fort "Milyutin."

Towards the bay, two shafts partially preserved, which sheltered the experimental installation—the Pauker system, a mechanism that optimized the reload speed of heavy guns from 5 minutes to 15 seconds. The construction of the Pauker battery was completed in 1879. The left flank of Fort "Grand Duke Konstantin" completed a chain of four batteries. In 1901, the right flank battery was built, of which part of the casemates and armory yards have survived to this day.

The fort did not participate in battles of the First World War and the Civil War. In 1924, the fort was renamed Fort "K" ("Roshal"). In 1934-35, two machine-gun pillboxes were built on the fort, and on the left flank, at the site of the 10" gun positions, concrete protective structures for four 45-mm guns were built, which during the Great Patriotic War shelled the approaches to the Oranienbaum bridgehead.

However, during the Great Patriotic War, it, so to speak, became a direct participant. From here, on the southern side of the Gulf of Finland, fire attacks were carried out against the aircraft of the Nazi "Luftwaffe." The defense was held by Soviet soldiers using two pillboxes obtained by the fort in the 1930s.

Throughout its existence, due to various historical circumstances, the original appearance of the fortress changed repeatedly. For example, the upper part of the fortress rampart, protected in front by a parapet (valgang), lacks guns, giving it an unfinished look. The casemates equipped with embrasures for all-around defense—should enemy troops break into the fortress—have been restored many times.

In the 1960s, Fort "Konstantin" was disarmed and, unfortunately, looted. Two decades later, a motor depot was established on the site of the fort. Before that, the builders of the protective structures complex drained a fairly large area around "Konstantin."

Currently, the historical and cultural complex "Fort Konstantin" is located in the central part of Kotlin. The fort is connected to the rest of the island by a constructed dam and a railway track. Today, it is one of the most significant regional centers in the country, continuing to develop. This situation is due not only to the undeniable beauty of the fort, including from an architectural point of view, but also thanks to the work carried out here.

From 2000 to 2007, annual electronic music festivals FORTDANCE were held at Fort "Alexander." Also, from 2003 to 2006, the festival organized a shore dance floor at Fort "Konstantin" with a capacity of up to 30,000 people "with high-quality 500-kilowatt sound, first-class laser and video shows, and a system of bars." Since 2006, Fort "Konstantin" has been developing as a cultural and tourist center and simultaneously as a yacht club. The yacht club is located near the main fairway of the Northern capital, close to the shipping facilities and the Saint Petersburg ring road.

Sources:

https://ru.wikipedia.org/wiki/Константин_(форт)

https://kronfort.com/guests/maps-fort-konstantin/

https://ruskontur.com/places/12498#fort«konstantin»:rozhdeniye-legendy