Her manners were dictatorial and insolent. She has the reputation of being remarkably sensible and clever; but I rather believe she derives part of her abilities from her rank and fortune, part from her authoritative manner, and the rest from the pride of her nephew, who chooses that every one connected with him should have an understanding of the first class.

– Jane Austen

Pride and Prejudice, Chapter 16. Charles Bingley is speaking to Elizabeth here about Lady Catherine. He sums up her character extremely accurately. There are many examples in the novel of her being authoritative and dictatorial with the other characters and using her rank and wealth to tell others what to do.