Say Yes to the Marquess by Tessa Dare (2014)

Another absolutely adorable romance in the Castles Ever After series. 

This one is about Clio, who has been engaged to diplomat and world-wanderer Piers for eight years and has had enough. Once she inherits a castle, she decides to go it alone. But Piers brother, former prizefighter and yes, rake, is trying everything he can to keep them together. Even though the chemistry between them is amazing. 

It's very cute and funny and romantic. I love how Dare combines the tropes of historical romance with strong heroines, dishy romance and the smallest, subtlest nods to contemporary culture. Fun fun!