Final answer:
Elmira Royster was Edgar Allan Poe's childhood friend and fiancée. They were engaged before his university years and rekindled their relationship later in life, getting engaged once more before Poe's death.
Step-by-step explanation:
Elmira Royster is significant to Edgar Allan Poe's life because she was Poe's childhood friend and they were engaged before Poe went to the University of Virginia. Unfortunately, Elmira's father intercepted Poe's letters to her, and she assumed Poe had lost interest, leading her to marry another man. Many years later, after the death of Poe's wife Virginia and Elmira's first husband, Poe and Elmira rekindled their relationship and became engaged again before Poe's untimely death.