The Elphbergs are a fictional royal family from the musical "A Little Night Music," created by Stephen Sondheim. They are central to the story, which explores themes of love, desire, and the complexities of relationships. The family's dynamics and interactions with other characters drive the narrative, highlighting the contrasts between youth and age, passion and practicality. The Elphbergs are particularly known for their connections to the character of Fredrik Egerman and his relationships with various women.