Naval history of the Caspian Sea
Naval-military history of the Caspian is relevantly new. Until the 18th century, the Caspian Sea as a waterway, had not served any major interests of its immediate coastal countries. As an isolated body of water it did not have significance for commercial and trade interests, which resulted in ignorance by the coastal states towards building military presence in order to protect economic interest. Moreover, territories adjacent to the sea had historically been dominated by steppe nations in the North and East such as Khazars, Kipchaks, Mongols and Kazakhs, Turkmens, and land powers in the South and West such as the states existed in the territories of current Iran and the Caucasus. These nations have never had any rich maritime culture and interest in exploration of waterways.
Despite late militarization of the Caspian, episodic sails of military ships and marauder rides took place in the sea during the course of history, most notably, by the Vikings in the 9-11th centuries and by the Cossacks in the 17th centuries. During 9-11th centuries Vikings (from Kyevian Rus) repeatedly sailed down the Volga River and attacked Caspian coasts.1 Pirate flotilla did not only limit itself with attacking coastal cities, and as it was in 943-944 they raided deep inside Azerbaijan and ravaged rich middle ages city of Barda. During 17-18th centuries, the Kalmucks, who were settled in the area north of Dagestan and west of the Volga, Cossacks of the Don region and Turkmen marauders repeatedly raided Iranian and Azerbaijani coasts of the Caspian Sea.  Raids of Cossack led by Stepan (Stenka) Razin were particularly disastrous for the inhabitants of the coastal regions of the Caspian Sea and most notably in 1666-1667 Razin attacked and plundered the Caspian cities such as Derbend, Baku, Farhadabad, Rasht.
Aiming to become transit country in the lucrative trade between East and West, starting from 17th century Russia began to seek the ways to control maritime trade in the Caspian. Having control over the maritime routes to Iran and to India was long a dream of Russian emperors. Russia became a Caspian power with conquest of the khanates of Kazan and Astrakhan by the 1560s. It attempted build a flotilla in Astrakhan in 1660s. However the first ships built there were burned down when the city was sacked by the rebelled Cossacks. The standing navy emerged in the Caspian Sea in the beginning of 18th century during the reign of the Russian tsar Peter the Great. In 1704 by decree of Peter the Admiralty was founded in Kazan and construction of ships for the Caspian Sea was begun making Russia the dominant maritime power in the sea ever since. During the campaign against Safavids (rulers of current Iran and Caucasus) in 1722-23, Peter ordered the construction of the navy- base in Astrakhan to strengthen the Russian presence in the sea. 1722-23 campaign of Peter resulted in peace treaty of St. Petersburg which gave all coastal areas of the Caspian Sea from Derbent up to Rasht to Russia. However treaty was not recognized in the Savafid capital. Indeed Russia had never had any effective control over the conquered territories. Consequently, owning the territories only on paper, Russia recognized Savafid rule over them with 1735 treaty hoping to get Savafid’s alliance against Ottomans. Thus, efforts launched by Peter did not produce Russian control of the sea, however, the Treaty of St.
Petersburg had come to signal Russia’s ambition to control the Caspian as a strategic necessity.
During 1740s, Nadir shah Afshar who consolidated his authority over current Iran and Caucasus after overthrowing Safavid dynasty attempted to build his flotilla in Rasht with the help of Englishman John Elton; however his assassination halted this attempt. John Elton stayed in Gilan after Nadir’s death hoping the complete the establishment of the flotilla, but he was also killed in 1751. Using the chaos in Iran emerged after Nadir’s death, Russian flotilla burned the ships prepared for Nadir’s Caspian flotilla in their stores near Rasht in 1751-1752.
The next round of fighting to control the Caspian coasts happened between Iran and Russia about 100 years after Peter the Great’s campaign. Gu- listan (1813) and Turkmenchay (1828) peace treaties signed after two major Iran-Russia wars gave the significant part of the Azerbaijani Caspian coastline from Derbent till Astara to Russia and Iran recognized Russian exclusive right to be the only power in the Caspian to maintain military ships in the sea. With the treaties Russia turned into an official monopolist of the military of power in the sea.
In 1867 Baku became the major naval base of Russia in the Caspian which retained this status until the collapse of the Soviet Union. Azerbaijani Democratic Republic (ADR) founded in 1918 after the fall of the tsarist Russian empire established its own Caspian flotilla, based on the vessels remained in Baku from imperial Caspian fleet. After the invasion of the ADR by the Soviet Red army in 1920 short-lived Azerbaijani flotilla was integrated into the Soviet Caspian Fleet.
After consolidation of the Soviet rule in the territories of the collapsed Russian Empire, “Persia and the Russian Socialist Federal Soviet Republic Treaty of Friendship” of February 1921 provided Moscow and Tehran with “equal rights of freedom of navigation in the [Caspian] Sea under their own flags.” With this treaty, maybe in ambiguous terms, but Iran’s right to have a navy on the Caspian Sea had been recognized. Guaranteed by a series of internationally recognized treaties (particularly those signed in 1927 and 1940), Iran and Russia exercised their rights to shipping, trade and fishing in the
Caspian.11 However, Iranian naval power never matched the military capabilities of the USSR in the Caspian Sea. USSR had been an unchallenged military dominant of the sea until 1991.
During the World War II Soviet Caspian fleet was used for landing troops in the northern Iran, as well as for protecting sea transportation routes against German air raids. Part of the Caspian fleet also relocated into Volga to participate in the operations against German troops. Caspian fleet also played an important role in securing supply routes from allied countries through Iran. After the end of the war Caspian remained as a testing ground of the Soviet naval weapons (and the new warships, including diesel submarines and unique airfoils) until the collapse of the USSR. 
-  F. Alakbarli, On Presence of Scandinavians in Caspian Sea during Middle Ages (9th-11th Centuries), International Medieval Congress IMC 2004, Paper 1123-c (12-15 July 2004), available at: http://www.aamh.az/alakbarli/index.files/vikings/Vikings.htm (last retrieved 4 February 2014).
-  G. Mirfendereski, A Diplomatic History of the Caspian Sea: Treaties, Diaries and Other Stories, 2001, pp.116-17, in G. Mirfendereski, Caspian Sea ii. Diplomatic history in modern times, Encyclopedia Iranica, September 14, 2004, available at: http://www.iranicaonline.org/articles/caspian-sea-ii-diplomatic-history-in-modern-times (last retrieved 4 February 2014).
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-  Ministry of Defense of the Russian federation, Caspian Flotilla, available at: http://eng.mil.ru/en/structure/forces/navy/associations/structure/forces/type/navy/kasp/history.htm (last retrieved 7 February 2014).
-  G Mirfendereski, (2001), pp. 116-17.
-  M. Axworthy, “Nader Shah and the Iranian Navy”, Encyclopedia Iranica, 20 December 2012, available at:http://www.iranicaonline.org/articles/navy-i-nader-shah (last retrieved 9 February 2014).
-  Константин Чуприн, От Гюлистанского мира до "Каспийского стража, Flot.com, 2009, available at:http://flot.com/nowadays/structure/caspianguard.htm?print=Y (last retrieved 11 February 2014).
-  G. Mirfendereski, (2001), pp. 116-17.
-  Agreement on joint exploitation (for 25 years) of fish resources of the southern coast of the Caspian Sea andT reaty of Warranties and Neutrality of 1927 and T reaty of T rade and Navigation of 1940.
-  S. Main, The Bear, the Peacock, the Eagle, the Sturgeon and the Black, Black Oil: Contemporary RegionalPower Politics in the Caspian Sea, Conflict Studies Research Centre, Caucasus Series 05/67, December2005, p. 22.
-  Константин Чуприн, От Гюлистанского мира до "Каспийского стража”, Flot.com, 2009, available at:http://flot.com/nowadays/structure/caspianguard.htm?print=Y (last retrieved 7 February 2014).