Borey-class submarines are to become the mainstay of the naval component of Russia's strategic nuclear deterrent, replacing the aging Typhoon-class and Delta-class boats. Russia expects a total of eight Borey subs to enter service with the navy by 2020.
The first two Borey-class nuclear subs, the Yury Dolgoruky and the Alexander Nevsky, were commissioned in January and December 2013 respectively. The fourth and fifth subs of the class, the Knyaz Vladimir and the Knyaz Oleg, are currently under construction at the Sevmash shipyard.