Queen Serenity was the the queen of the Moon during the Silver Millenium. She is the mother of Sailor Moon.
Queen Serenity was the queen of the Moon Kingdon during the Silver Millenium. During most of her reign, there was peace on the moon. Until, Queen Beryl and the Negaforce attacked the Moon, destroying the Moon Kingdom. So in an act to protect the future of the Moon and Earth, as well as her daughter, Queen Serenity used the Crescent Moon Wand to banish Beryl and the Negaforce from the Moon.
We don't see enough of Queen Serenity to see her character evolution, as she stay's pure and good throughout her appearences. She died before the beginning of the series, and we only see glimpses of her throughout the series, especially Season 1.
Crescent Moon Wand Mastery - Queen Serenity has shown to have mastery over the power of the Imperium Crystal as well as the Crescent Moon Wand.