Barbara Cartland 
Love Rules [EPUB ebook] 

When her father orders her to marry a cousin of the Russian Czar, whom she does not even know, let alone love, Princess Margarita of Altauss is horrified. Forced to travel to St. Petersburg, she demands that her English friend, Paulina Handley, daughter of a British Diplomat, goes along with her as her Lady in Waiting.
Very experienced in the ways of the world and of love, her father, Sir Christopher Handley, urges Paulina to beware Russian aristocrats and Royalty, who would make effusive declarations of love, but would never actually be allowed to marry a commoner.
However, no sooner than she has arrived in St. Petersburg with his words still ringing in her ears, Paulina falls head over heels in love with the Princess’s brother, the handsome Prince Maximus – and he with her.
To her chagrin though, the Prince must return to the Caucasus, scene of his recent heroism in battle and, anyway, how can she, a commoner, ever marry a Prince?
So, before it even begins, their love seems to be doomed.