Hamlin, Hamlin & McGill was founded by Chuck McGill and the father of Howard Hamlin; Chuck mentored Howard as he took his bar exam and joined the firm. Later, Chuck convinced his younger brother Jimmy to move to New Mexico to make a legitimate living while working in HHM's mail room. It was there that Jimmy met Kim Wexler.
When Jimmy earned a law degree from a shady diploma mill and passed the bar exam (after failing twice), he sought a job at HHM. However, Chuck -- alarmed at the idea of his brother, a former con artist, practicing law -- used Howard to block Jimmy's chances of advancement. Jimmy eventually left HHM and began a thankless career as a general solo practitioner, taking on any work he could, including working with the public defender and writing wills.
A year-and-a-half before the start of the series, Chuck took leave from HHM over his electromagnetic hypersensitivity. HHM gives him a weekly stipend of $26,000, which Jimmy feels is an attempt to cheat Chuck out of his rightful share. After Jimmy confronts Howard, HHM gives Chuck a new stipend of $857. Meanwhile, Jimmy fails to land Craig and Betsy Kettleman, a couple accused of embezzling county funds, as new clients. They subsequently turn to HHM.("")
Jimmy spends illicit money on a billboard advertisement which shares obvious visual similarities to HHM's brand, leading the firm to sue Jimmy for trademark infringement. When Jimmy is ordered to remove the billboard, he stages an emergency in which he "rescues" the worker taking down the advertisement. Howard and Kim see through the ruse, but the incident gives Jimmy exposure in the local media and boosts his popularity.("")
When the Kettlemans reject Kim's proposed plea deal and drop HHM, Jimmy learns that the firm demoted her to document review, a.k.a. the "corn field," as punishment. To help Kim, Jimmy has an acquaintance, Mike Ehrmantraut, steal their ill-gotten money, to be delivered to the district attorney. Jimmy successfully pressures the Kettlemans into taking their case back to HHM and accepting Kim's proposal.("")
While soliciting elderly clients, Jimmy discovers that the Sandpiper Crossing nursing home is overcharging its residents. Jimmy takes his findings to Chuck, who agrees that Jimmy has built a solid case. Chuck is invigorated enough by the Sandpiper investigation to work through his EHS and returns to the firm. However, Jimmy learns that HHM will handle the case themselves while he will be cut out in exchange for a finder's fee. Jimmy later agrees to the deal when he discovers Chuck's role in holding him back when he worked at HHM.("")("")
Jimmy accepts a new job with the Santa Fe firm of Davis & Main, which is working with HHM in litigating the Sandpiper case. Chuck sits in and "bears witness" at a meeting between HHM and D&M as Jimmy discusses his clients.("")
When Jimmy airs a sensationalistic TV commercial for D&M without approval from their partners, the ripple effect is felt at HHM. Howard and Chuck punish Kim -- who had vouched for Jimmy -- by demoting her to doc review for a second time. Feeling that Chuck is going after Kim as a tactic to force him into quitting law, Jimmy tries to convince Kim to sue HHM, which she declines. Chuck later allows for Kim to be reinstated, but she is still treated coldly by Howard.("")("")("")
Kim eventually resigns from HHM to launch twin solo firms with Jimmy and is hired by Mesa Verde Bank and Trust, developments which rattle Chuck. He manages to persuade Mesa Verde to stay with HHM at Kim's expense. In retaliation, Jimmy copies Chuck's Mesa Verde files and forges incorrect addresses on them before they are mailed to the state regulator. At a hearing, confusion over the address leads to a six-week delay in the opening of Mesa Verde's new branch. Mesa Verde fires HHM and returns to Kim.("")("")
Chuck, having compelled Jimmy to confess to forging the Mesa Verde files on tape, tries to set him up for a break-in and subsequent disbarment. However, the scheme ends in disaster when Jimmy exposes Chuck's EHS as a delusion, causing Chuck to lash out on the stand at Jimmy's bar hearing. Later, Jimmy approaches a malpractice insurance agent he shares with Chuck and discloses his brother's mental problems and breakdown in court.("")("")
Due to Chuck's meltdown at the bar hearing, word of his illness gets out and Howard spends the next two weeks hosting three meals a day with HHM's clients in order to perform damage control. Furthermore, due to Jimmy revealing Chuck's condition to his malpractice insurer, they seek to double premiums on every practicing attorney at HHM. Unable to trust Chuck's judgment, Howard attempts to force him into retirement, only for Chuck to retaliate by suing HHM for breach of contract.("")("")
Howard calls out Chuck for putting his personal vendettas ahead of HHM's well-being, and for betraying their friendship in the process. He hands Chuck a severance check for $3 million (the first of three installments), which comes out of his own pocket and thus eliminates Chuck's financial leverage over HHM. Chuck is forced to stand by and watch as Howard tells HHM staff of his immediate departure. Soon after, Chuck suffers a severe relapse of his EHS delusion and lets his house catch fire, committing suicide.("")