Reinette Poisson, aka Madame de Pompadour

The Palace of Versailles, 1746. Reinette Poisson, the king's mistress, stood at the side of the ballroom with a frown on her face, watching the petite brunette in the red dress clumsily flirting with King Louis himself. With a frustrated growl, she swept across the room toward the pair.
"You really must see the horses sometime..." Louis said, trailing off as he saw Reinette approaching. She raised a hand to silence him as he made to speak, grabbing the young woman by the arm and forcibly dragging her toward a side door.
"Blimey, you've got a strong grip," the woman commented, a hint of a smirk on her face. Reinette ignored the comment, pulling her through the door and shutting it behind them. The sounds from the adjoining room were quickly cut off as the door shut, leaving the two women alone.
"I don't know who you are," Reinette said, rounding on the smaller woman. "But between myself and his wife, His Majesty has more than enough female attention without you butting in."
"Is that right, Miss Poisson?" the brunette replied, her smile widening. "Maybe the two of us should settle things right here then, woman to woman. See if the rest of your body is as strong as that wrist." Reinette barked out a laugh, sizing up her rival as she did.
"Why not?" she replied after a moment's consideration. "One can't always expect a dashing hero to show up to vanquish the monsters, after all. I shall prove to you that I am more than capable of fighting my own battles, madame..."
"Oswald," Clara replied. "Clara Oswald. I've heard good things about you, Reinette. Let's see what you're made of!"