Reading right now: "The Winter Palace" by Eva Stachniak

"When Vavara, a young Polish orphan, arrives at the glittering, dangerous court of the Empress Elizabeth in St Petersburg, she is schooled in skills ranging from lock-picking to love-making, learning above all else to stay silent - and listen.

Then Sophie, a vulnerable young princess, arrives from Prussia as a prospective bride for the Empress's heir. Set to spy on her, Vavara soon becomes her friend and confidante, and helps her navigate the illicit liaisons and the treacherous shifting allegiances of the court. But Sophie's destiny is to become the notorious Catherine the Great. Are her ambitions more lofty and far-reaching than anyone suspected, and will she stop at nothing to achieve absolute power?"
(text from the book cover "The Winter Palace" by Eva Stachniak, published by Black Swan, 2012, 512 pages.)