The Second Dynasty was a period in Klingon history, nearly eight centuries ago, that ended with General K'Trelan assassinating Emperor Reclaw then later putting to death all the members of the Imperial Family. The next ten years that followed, the Empire was ruled by a council elected by the people, this is referred to as "The Dark Time" by Klingon historians. (DS9:"You Are Cordially Invited...")
- The Klingon Second Dynasty is not associated with, nor should be confused with the Second Empire.