The 4th Region[1] or the Northern Fleet[2] (Persian: ناوگان شمال) is the flotilla of the Islamic Republic of Iran Navy in the Caspian Sea.

[3] He saw the flotilla as an essential tool to secure maritime trade and defend coasts of his northern lands, where Turkmen pirates often attacked.

[6] Englishman John "Jamal Beig" Elton supervised the shipyard located in Anzali,[6] as well as additional facilities in Lahijan and Langarud.

[8] By the end of the 19th century, one royal yacht –"a small dilapidated paddle-wheel steamer" named Nasereddin– was the only asset of the Persian navy in the Caspian Sea.

[8] The Russo-Persian Treaty of Friendship signed in 1921, eased Iranian efforts to reestablish its Caspian fleet once again, despite the fact the Soviets unilaterally assumed the authority for a preemptive attack on Iran in case they deemed Caspian security at stake, and Iranians promised to oust non-Iranians in their naval service in the event of harming Soviet interests.

[8] During the 1990s, Iran started rebuilding its fleet from scratch[10] after declaring that it assumes the right to maintain military presence in the Caspian.

[12] In September 1998, Admiral Abbas Mohtaj stated "a stronger presence in the Caspian Sea is among the future programs of the Navy".