“I don’t believe in happy families,” Pat Conroy tells us in his luminous, unsparing new memoir, “The Death of Santini.” “A family is too frail a vessel to contain the risks of all the warring impulses expressed when such a group meets on common ground.” In the case of the Conroy family — as colorful and contentious a bunch as you could hope to encounter in either literature or life — those sentiments ring absolutely true. Conroy has been writing about his family and their internecine wars for nearly 40 years. It has been his central subject, and he has pursued it with an obsessive’s attention to each recollected detail. On the evidence of his latest book, Conroy may finally have put his endless — and endlessly fascinating — story to rest.

The public face of that story began with the appearance of Conroy’s novel “The Great Santini” in 1976. As most readers know, the novel’s patriarch protagonist, Bull Meecham, was a lightly fictionalized version of Conroy’s own father, Col. Donald Conroy, USMC. Brutal, commanding and charismatic, the elder Conroy was a man who legitimized such cliches as “larger than life.”

The Conroy/Meecham of the novel was a physically imposing despot who inflicted extreme and inexcusable violence on his wife and children. He was also a genuinely heroic figure given to surprising, if infrequent, moments of kindness. These kindnesses, though, were the most fictionalized elements in the novel. Responding to an editor’s request to soften his portrait of this hard-edged, take-no-prisoners character, Conroy complied. “To make my father human,” he acknowledges here, “I had to lie.”

Despite this softening, the novel touched off the first of numerous firestorms within the Conroy clan. Many relatives resented what they saw as a betrayal of family secrets. Don Conroy initially expressed both hurt and outrage, denying what he called “these weird fantasies of my oldest son.” But in a surprising turn of events, the elder Conroy soon became his son’s staunchest defender, embracing — with charm and good humor — his newly public role as the real Great Santini. It marked the start of an extended process of reconciliation that would take decades to complete.

“The Death of Santini” is subtitled “The Story of a Father and His Son.” While that is certainly an accurate description, there is a good deal more to the book than that. The uneasy, slowly evolving relationship between Don and Pat Conroy provides the narrative’s central thread. At the same time, it serves as the armature for a wide-ranging exploration of the secret corners and often tragic histories of a complex family.

”The Death of Santini: The Story of a Father and His Son” by Pat Conroy. (Nan A. Talese)

Two genealogical streams converged to create the feisty, embattled Conroy clan of Pat’s generation. His father’s side emerged from the urban wilderness of Chicago, which produced a crowd of boisterous Irish Catholics of whom Don Conroy, the swaggering Marine, was the epitome. The maternal side emerged from the heart of the American South and produced a number of genuine eccentrics. Many of them have appeared, in one guise or another, in Conroy’s previous work. Perhaps the most vivid is Conroy’s grandmother Stanny, who acquired lifelong notoriety when, in the depths of the Depression, she abandoned her husband and four children to search for a new life in Atlanta. She would later become one of the most memorable supporting characters in “The Prince of Tides.”

One of those abandoned children was Frances “Peg” Peek, who would, in time, marry Don Conroy, a handsome fighter pilot from a very different world.

Their epic misalliance would result in seven children, eventual divorce and a lifetime of recriminations. Her greatest legacy to her children — Pat, in particular — would be her sustaining love of language and literature. A true Southern beauty whose literary role model was Scarlett O’Hara, she was also parsimonious, emotionally remote and plagued by a sense of social inferiority. Most significantly, she was a battered wife who fought to keep her abusive marriage a secret from the world. Her protracted death from leukemia is one of the emotional centerpieces of the book.

“The Death of Santini” gathers up these and many other narrative strands to create a cohesive portrait of one American family’s volatile history. It follows Don Conroy through his astonishingly benign second act and ends with a moving, powerfully described account of his lingering death from colon cancer and the subsequent Conroy-style funeral.

Like so much of the author’s earlier work, this highly charged act of remembrance explores the sources of what he once called “the disfigurements of spirit” that inevitably arise from childhoods marked by physical and emotional abuse. The cost of membership in Santini’s family was always high, and the narrative is littered with accounts of mental illness, multiple breakdowns and familial estrangements, culminating in the suicide of the youngest Conroy sibling, Tom.

Despite the inherently bleak nature of so much of this material, Conroy has fashioned a memoir that is vital, large-hearted and often raucously funny. The result is an act of hard-won forgiveness, a deeply considered meditation on the impossibly complex nature of families and a valuable contribution to the literature of fathers and sons.

Sheehan is the author of “At the Foot of the Story Tree: An Inquiry into the Fiction of Peter Straub.”

The Death of Santini

The Story of a Father and His Son

By Pat Conroy

Doubleday, 338 pp. $28.95