The series follows the adventures of a space-faring crew on board the Galaxy Class starship USS Enterprise (NCC-1701-D), the fifth Federation vessel to bear the name and registry and the seventh starship by that name. The series is set about 70 years after the final mission of the original Enterprise crew under the command of James T. Kirk. The Federation has undergone significant internal changes in its quest to explore and seek out new life, adding new degrees of complexity and controversy to its methods, especially those focused on the Prime Directive. The Klingon Empire and the United Federation of Planets have ceased wartime hostilities and become galactic allies, while more sinister foes such as the Romulans and the Borg take precedence on the series.