When I bought Duchess by Night I also bought When the Duke Returns. I think the owner of the secondhand bookshop recommended them as part of a series. I am glad I only bought two as though they were enjoyable light reads they were not really my style. Something easy for reading on a plane journey. No great plot to get your mind around no in depth characters. Having said that I can still say I enjoyed them.
From the book cover:
For the Duke of Cosway it was a marriage of convenience, for his bride it was anything but. Isidore has waited many, long, frustrating years for her mysterious husband to come back from exploring the world. They were married by proxy when she was just a child and she yearns to actually meet the duke himself.
Until he returns.
Cosway is not what she expected. He won’t powder his hair, has little time for cravats and seems frightfully keen in running around the countryside in nothing but short trousers. Even worse, he takes one look at Isidore and offers an annulment.
But Isidore will not give up her claim to the title – or the duke himself – without a fight. And while she tries to establish whether he is worth sacrificing her virtue and dignity for, the duke begins to discover that there may be more adventures in marriage than in all of the rest of the world.
You can find out more about this series here.
Gippsland Granny 
Sometimes it’s nice to read something that doesn’t challenge the little grey cells too much.
I couldn’t agree more.