Age
We are never given explicit information about when Mr. Wickham was born, but we can anticipate that he's likely around the same age as Mr. Darcy Senior, since their sons are about the same age. We do know he dies five years prior to the opening of the novel.
Family and Situation
Mr. Wickham was the husband of Mrs. Wickham and father of George Wickham. We never hear of him having any children besides George.
As his employer, Mr. Darcy, would ultimately have a close relationship with George, it is unclear what the father-son relationship may have been. Fitzwilliam Darcy also tells us that Mr. Wickham was “always poor for the extravagance of his wife,” suggesting that either they were in frequent conflict or he turned a blind eye to such transgressions.
George Wickham tells us “My father began life in the profession which [the Bennets'] uncle, Mr. Phillips, appears to do so much credit to—but he gave up everything to be of use to the late Mr. Darcy and devoted all his time to the care of the Pemberley property. He was most highly esteemed by Mr. Darcy, a most intimate, confidential friend. Mr. Darcy often acknowledged himself to be under the greatest obligations to my father's active superintendence, and when, immediately before my father's death, Mr. Darcy gave him a voluntary promise of providing for me, I am convinced that he felt it to be as much a debt of gratitude to him, as of his affection to myself.”
Fitzwilliam Darcy mentions him in his letter to Elizabeth, describing him as "a very respectable man, who had for many years the management of all the Pemberley estates, and whose good conduct in the discharge of his trust naturally inclined my father to be of service to him." Caroline Bingley, Mrs. Reynolds and Lady Catherine all characterize him as “the late Mr. Darcy’s steward."
