Mr. Wickham is a young man in his mid to late 20's. He was the son of the late Mr Darcy's steward. His father died which Mr. Darcy told him as his second son. He roughly around the same age as Fitzwilliam Darcy.
During the novel, he manages to seduce everyone around him with his polite and cheery manners, making him a true Austen villian. All the ladies love his looks, especially Eliza and Lydia. He manages to entrance Eliza, by feeding into her dislike of Mr. Darcy, until she learns the truth about Mr. Wickham's past, and begins to doubt his intentions. Unfortunately, Eliza does not warn her family about the real Mr. Wickham, and is thus unable to save Lydia from disgrace (Lydia and Wickham were conducting very scandalous affairs that came to light when Lydia went to Brighton). He and Lydia later marry, but do not live in marital bliss, as they are always out of money, and always have to look for work.