The secret countess if quite possibly my favourite book of all time. Set in the 1940s it tells the story of Anna, a young Russian Countess who is forced to flee Russia and moves to England. There she has to work as a maid at a manor house where no one can know her identity.
I love this book because it is so different from all the dystopian, typical teen fiction books that condense our bookshelves today. The Secret Countess is sweet and romantic but also helps teach about history. The books helped me understand more about what it was like in those times as well as causing a few tugs on my heart strings.
I love all of Eva Ibbotson's books and whilst this is my favourite I definitely recommend checking out The Morning Gift - which used to be my favourite - and A Company of Swans. All have similar premises, with romance stories being set in similar eras.