'Boreas', NATO reporting name Dolgorukiy), are a series of nuclear-powered ballistic missile submarines being constructed by Sevmash for the Russian Navy.

The vessels were developed by Rubin Design Bureau and are being built by Russia's Northern shipyard Sevmash in Severodvinsk.

[10] The launch of the first submarine of the class, Yury Dolgorukiy (Юрий Долгорукий), was scheduled for 2002 but was delayed because of budget constraints.

The vessel was eventually rolled out of its construction hall on 15 April 2007 in a ceremony attended by many senior military and industrial personnel.

[11] Yuriy Dolgorukiy was the first Russian strategic missile submarine to be launched in seventeen years since the end of the Cold War.

[16] By late October the Russian Pacific Fleet was fully prepared to host Russia's new Borei-class strategic nuclear-powered submarines.

[24] After long delays finally the lead vessel, Yuriy Dolgorukiy, joined the Russian Navy on 10 January 2013.

[26][27] Borei class includes a compact and integrated hydrodynamically efficient hull for reduced broadband noise and the first ever use of pump-jet propulsion on a Russian nuclear submarine.

[29] The acoustic signature of Borei is significantly stealthier than that of the previous generations of Russian SSBNs, but it has been reported that their hydraulic pumps become noisier after a relatively short period of operation, reducing the stealth capabilities of the submarine.

[44] The contract for five modified 955A submarines was delayed several times due to price dispute between the Russian Defence Ministry and the United Shipbuilding Corporation.

[47] According to Sevmash official, Vitaliy Bukovskiy, all Borei-A submarines are to be equipped with aspen banyas able to accommodate 3–4 people.

[38] The Project 955B was expected to feature a new water jet propulsion system, an upgraded hull, and new noise reduction technology.

[52] It will also have 20% lower displacement compared to current ballistic missile submarines, with a planned crew of around 100 people, and being 134 meters in length.