No they didn't. The first half of season 1 is for book 1 (book 2 is the second half). Book 3 and book 4 make up season 2. Season 3 is based of book 5 and half of book 6. Season 4 shows the rest of book 6 and 7. Season 5 wasn't really based on the books as they made stuff up. It has an 11 year time jump but contains some of book 8. There is a total of 12 books in the poldark series but unfortunately they weren't all put into the series. I wish they had done more seasons! :)