Answer:
to inform readers about the history of Rome and Sparta and how they built their empires
There are many sides to Lady Macbeth, and although there are many more negative than positive qualities, I will try to list some of them nevertheless.
Negative: she is ruthless, and stops at nothing to achieve her goals. She wants her husband to become king, and isn't afraid to be an accomplice in a murder to get what she wants. She is manipulative, constantly controlling her husband to do what she wants him to do.
Positive: I'd say that in the end, one of her positive qualities is her guilt - she feels guilty for all the murders she took part in, which shows that she is human after all, with conscience. I guess that her ambition could be both a positive and negative quality, because she is very strong and powerful.
