If a dozen masterpiece Renaissance sculptures, made in an unknown and wildly unorthodox style, suddenly turned up in the Italian countryside, the find would make the news. When the equivalent of such a discovery occurred in the early 1970s, however, it went all but unreported because the sculptures were from Africa, and only some startled scholars and collectors took note. Now, more than 40 years on, the news finally hits New York with the arrival of “Warriors and Mothers: Epic Mbembe Art” at the Metropolitan Museum, one of the great sculpture shows of the season.

Here’s how the story began. In Paris in 1972, the gallery owner Hélène Kamer, who specialized in African art, made a routine call on a Malian dealer who was in town to display his wares. Among his items for sale was a spectacular wood-carved female figure, majestic but weatherworn — surface erosion made it look as if it were wrapped in bandages — and of a type Ms. Kamer couldn’t place. The dealer was tight-lipped about its source but said he could get more.

He did. By the summer of 1973, he had delivered 12 figures and some information: They had been made by the Mbembe (m-BEM-beh) living in southeastern Nigeria, near the border of Cameroon. The religious tradition that had produced the work had been abandoned under colonialism. The sculptures, when he came across them, had been moldering away unattended.

The following year, Ms. Kamer exhibited the work. Within a circle of African art devotees, it caused a sensation, and there was reason to think the excitement might spread: Just before the show opened, she sold a piece to the Musée des Arts Africains et Océaniens (now part of the Musée du Quai Branly).

Then, mysteriously, the supply dried up. The Malian dealer was untraceable; Ms. Kamer never heard from him again. A few more pieces came on the market, in bad shape, but that was it. The 14 examples at the Met, including the original dozen, represent all the fully intact stand-alone figures known.

Even with the prospect of further collecting unlikely, interest continued. Tests revealed that some of the Mbembe pieces were from the 17th and 18th centuries, among the oldest wood carvings from Africa. A pair that belonged to the Ethnological Museum in Berlin dated to around 1550, when Michelangelo was completing his late “Deposition” in Florence. But the Berlin examples — which didn’t travel to the Met — are distinctive in another way, too. They’re not free standing. They’re basically very high reliefs cut into either end of an immense tree trunk that had been hollowed out to make a drum. Most of the Met figures had similar origins; the rough wood plinths they sit or stand on are remnants of drums, now vanished, to which they were attached.

Drums of monumental size and heft were central to Mbembe culture and had both social and spiritual uses. With a resonance that carried for miles, they were all-points broadcasting devices, announcing deaths, spreading word of festivals, calling men to war. In addition, their vibrations penetrated the afterlife, summoning the dead in times of crisis. Carved drum figures have been interpreted as ancestor portraits, which had communicative functions of their own. They kept the community in visual touch with its history, and they reinforced and amplified yin-yang modes of heroic behavior: killing and nurturing.

A male figure placed just outside the exhibition space in the Michael C. Rockefeller Wing is a three-foot-tall nugget of radiant hostility, an aggressive muscle tensed to strike. Broad and squat, he stands holding a severed head and baring his teeth. He’s believed to be the portrait of the 17th-century Mbembe chief Appia, who founded a village that still carries his name. After death he remained a communal protector and the figurehead of a local men’s society that required prospective members to decapitate an enemy to earn admission.

Although the warrior-hero concept seems straightforward, no two images are alike. Another leader, Mabana, is shown seated, balancing a head like a bowling ball on one knee and leaning back appraisingly. In a late example, pretty clearly from the early 20th century, the subject clutches a rifle and wears a bowler hat on his outsize head. But the figure of the chief N’Ko has no head at all. According to legend, he asked that the head be cut from his portrait and buried with him so that men of the future, encountering the statue, might be reminded of the risks he took to protect his people. Here aggression is spun as self-sacrifice and civic duty.

The duty to perpetuate and expand the community is the animating theme of Mbembe female images, which dominate the show. In a beautiful example acquired by the Met in 2010, a young woman with a toned body and grave oval face holds a child horizontally across her lap; in another, similar image, the child sits upright, echoing the mother’s form.

You’ll find an equivalent of this pose in a 12th-century French carving of the Virgin and Child, sometimes referred to as the “Morgan Madonna,” in the Met’s medieval galleries. This maternal image embodies a theological type known as the Throne of Wisdom, in which the Virgin serves as the passive support and the child, the active sapient force. In comparable Mbembe images, women seem to be — simultaneously and magnificently — active and passive.

In one sculpture seriously altered by corrosion, however, gender is impossible to determine, and meaning is out of reach. Male or female, the figure sits on a surviving chunk of the original drum, as if on a bench. The hands, which may once have held something, are empty. With its lower legs missing, the body assumes a kind of meditation pose. The face, ground down by who knows what pressures, looks Buddhistic.

This is the sculpture purchased from Ms. Kamer by the Musée des Arts Africains et Océaniens before the 1974 show, making it the first free-standing Mbembe figure to enter a Western art museum’s collection. It may well have felt like a chancy buy back then, but its status has since become high. Although on loan for the Met show, it is usually found installed among a select group of African objects in the Pavillon des Sessions at the Louvre, a permanent gallery created to display representative masterpieces of non-Western art within a predominantly, even quintessentially, Western context.

A Mbembe work is an interesting choice for that honor. One thing that has intrigued people from the start is how visually unlike most other African art this art is. Another is how easily Mbembe sculpture evokes Western references: to Giacometti, German Expressionism and so on. That an atypical African tradition has been selected to represent Africa at the Louvre says at least something about how history and concepts of beauty continue to be shaped by a Western perspective.

Yet overriding all such concerns is the sheer charisma of Mbembe work, so evident and irrefutable in “Warriors and Mothers,” organized by Alisa LaGamma and Yaëlle Biro, curators in the museum’s department of the arts of Africa, Oceania and the Americas. And that charisma is layered and complicated, generated by the imaginative power of the sculptures and the artists who made them, but also by traces left on those objects by the passage of time. Once solid forms are now fragile, and in spots transparent, shells.

Fragility has its appeal. Western culture is in love with the romance of ruins. At the same time, I can think of few other groups of sculpture that better demonstrate the notion, fundamentally foreign to that thinking, of an aesthetic of transiency: the idea, amounting to a principle, that the most profound art is meant to crumble in the hand and live on in the mind.

(the New York Times)