[History]
Real Name: Sarah
Real Father: unknown summoner
Real Mother: Jane
Real Birthplace: Madain Sari, the Village of Summoners
As stated above, she never really was a princess. The tale of how she came about to be a princess is mystifying, yet sorrowful. Around six years after Sarah was born, the village where she lived at the time, Madain Sari, was attacked and destroyed by the legendary airship, the Invincible. Badly injured, her father sent Jane, Sarah's mother, and Sarah on a rickety boat to flee Madain Sari, in an effort to survive. In the boat as they sailed, Jane knew she could not survive any longer, so she tried her best to steer the boat to land, then she died with Sarah in her arms, unconscious.
The place where she landed the boat, was, incidentally, Alexandria. Alexandria was named after the great Holy Summon Alexander that lay dormant beneath it after many failed attempts to summon it made by the present Summoners' ancestors 500 years ago. Shamed, they built a city around the place where they failed to summon Alexander and named it 'Alexandria.' They broke up the gem used to summon it into four parts, thus forming the Desert Star (Cleyra), Falcon Claw (-I forgot the location-), Memory Earring (Madain Sari), and the Silver Pendant (Alexandria) which Sarah was given to wear, supposedly a royal heirloom... but we know better!
Eh, back to the story now... (cough, cough). Little Sarah was found in the boat by a few townspeople. Coincidentally, Brahne's daughter, the real Princess Garnet, had passed away due to some illness, and (the plot thickens), she looked exactly like Sarah, apart from the fact that Sarah had a Summoner's Horn upon her head. The royal couple and Dr. Tot were informed, and they came to the site. Amazed at how Sarah resembled the dead princess, the Royal Couple decided to raise her as their daughter, but to do that, they had to cut off the horn first. Of course this caused a whole lot of pain and tears for the poor little girl. After it was through with, Sarah was renamed Garnet Til Alexandros the 17th, and was officially the Alexandrian Princess, heiress to the throne.
As she was very young at the time all this happened, she gradually forgot everything and grew up assuming she was the Princess Garnet Til Alexandros the 17th. The only thing that remained to haunt her of her past were the recurring dreams she had and the mysterious song she sang whenever she was alone ("A song I always heard in my childhood..." - when Zidane questions her about the haunting melody). A piece of evidence that this story is true is when she first set foot in Madain Sari (at the time introduced as Eiko's home), she commented that the place was 'vaguely familiar.'