The Royal Navy is the principal naval warfare service branch of the British Armed Forces. As of January 2021, there are 79 commissioned ships in the Royal Navy. Of the commissioned vessels, twenty-three are major surface combatants (six guided missile destroyers, thirteen frigates, two amphibious transport docks and two aircraft carriers), and eleven are nuclear-powered submarines (four ballistic missile submarines and seven fleet submarines). In addition the Navy possesses thirteen mine countermeasures vessels, twenty-six patrol vessels, four survey vessels, one icebreaker and one historic warship, Victory. The total displacement of the Royal Navy is approximately 445,200 tonnes.