One important minor character is Miss Mary King. We first learn about Miss King around Chapter 4 of Volume 2. Elizabeth informs her aunt Gardiner that Wickham is pursuing Miss King because she has just inherited 10,000 pounds. Later, when Elizabeth returns from visiting Charlotte in Kent, we learn that Miss King's uncle has taken her to Liverpool, out of Wickham's reach.
Another important minor character is Colonel Forster. Colonel Forster is in charge of the regiment staying in Meryton. Lydia becomes close friends with his wife Harriet, another minor character, and is invited to accompany them to Brighton. Colonel Forster was believed by Mr. Bennet to be a "sensible man" who would keep Lydia "out of any real mischief" (Vol. 2, Ch. 18). However, we soon learn that Bennet's analysis of Colonel Forster's character was wrong and that he failed to look after Lydia, allowing her to run off with Wickham.
Colonel Fitzwilliam is Darcy's cousin and another important minor character. We meet him when Elizabeth visits Charlotte at Huntsford in Kent. He and Darcy have arrived to visit their aunt, Lady Catherine de Bourgh, at Rosings Park (Vol. 2, Ch. 7). He admires Elizabeth very much and would like to marry her, except that he is the second son of an Earl, with no real fortune of his own. Therefore, he must marry for money, as he states to Elizabeth, "There are not many in my rank of life who can afford to marry without some attention to money" (Vol. 2, Ch. 10).
Other minor characters are: 1) Anne de Bourgh, the daughter and heiress of Lady Catherine de Bourgh who never speaks a word; and 2) Mr. Denny, a soldier in the militia that Lydia flirts with.