Julietta's Storm

(from ebookjapan):

Princess Julietta of Yulia was at the height of her happiness as the bride of the Crown Prince of Kolwei, who was very close to her sickly brother, Prince Henry. In these days, poverty spreads among the people of Yulia, and soon the peasants rise up in revolution.

The name of the young man leading the revolution is "Black Wolf. The king and queen die on the executioner's block, but somehow the Black Wolf saves the lives of Julietta and her siblings.

But this is only the beginning of a stormy life for Julietta.