I initially picked up the book thinking it would have an introduction covering the background and history of the period surrounding the letters, with the majority of the text being the actually letters. Much to my surprise, it was quite the reverse. The history of the period and mystery surrounding the letters was nicely explained to the level of those who are not a fan of reading about history (or herstory). The letters did take me back to times when I have felt used and rejected by those I thought had more than a passing fancy. I don't agree with one of the reviews that Mariana should have "just gotten over it" as it applies contemporary ideas of love and sex on the past. The reviewer seems to have forgotten that Mariana spent the majority of her life in a convent with little access to the outside world and was subject to different rules governing propriety.
I would recommend this to people who want a light reading on the Portuguese Letters.