For centuries, ancient Egypt seemed a marvel of unchanging continuity to professional and amateur scholars alike, a society defined by tradition and cultural stasis. As late as 1975, an architecture critic wrote of its tombs and temples what was generally believed of the culture as a whole: “In the architecture of the Nile, although the hand never fails, the stimulus of intellectual curiosity, the tension that springs from avid enquiry, is often absent.”

A luxuriously large exhibition devoted to the Middle Kingdom period of Egyptian civilization, on view at New York’s Metropolitan Museum of Art, dismantles that prejudice thoroughly. “Ancient Egypt Transformed” looks at one of the least-appreciated periods of the 3,000 years of ancient Egyptian history. The Middle Kingdom lasted not quite four centuries, from about 2030 to 1650 B.C., and much of its architecture is lost. But it was also a period of significant cultural change, in ideas about kingship and religion, social status and class, and in the means and details of artistic expression. Drawing on the collections of 37 museums in the United States and abroad, it features 230 objects, many of them exquisite, some of them colossal and all of them revelatory.

The shorthand history of Egypt, created by 19th-century Egyptologists, divides the culture into three kingdoms each with multiple dynasties, the Old Kingdom (which gave us the great pyramids), the Middle Kingdom (from the mid-11th to the 13th dynasties) and the New Kingdom (which witnessed the greatest prosperity and extension of the Egyptian empire). In between were Intermediary Periods, often marked by fragmented or weak central government, and before and after were long periods of cultural formation and dissolution. The Middle Kingdom witnessed the reconsolidation of central government under dynasties that emerged from the south of the country, reunifying Upper and Lower Egypt and reclaiming much of the culture, expressions of power and habits of kingship forged during the Old Kingdom.

Among other things, they buried their pharaohs in pyramids, but alas, they built them not of solid stone, as did the Old Kingdom pharaohs, but of mud brick lined with stone. When the exterior limestone casing was removed, stolen or repurposed, the soft inner cores of the Middle Kingdom pyramids were eroded and often lost. But Middle Kingdom elites also built rock-cut tombs and stone temples, military facilities and colossal statues, and many of these remain in various states of preservation.

The exhibition opens with a statue, more than eight feet tall, of Mentuhotep II, an 11th-dynasty king who reigned for more than half a century and is considered the founder of the Middle Kingdom. The statue is smooth, imposing and opaque, with crudely rendered feet and arms and knees barely protruding through a veil of impassive stone. It is a deliberately archaic form, referring to styles that were perhaps 600 to more than 1,000 years old at the time of its carving.

Lintel of Senwosret I Running Toward the God Min (detail). Limestone. Twelfth Dynasty, reign of Senwosret I (ca. 1961–1917 B.C.). (Anna-Marie Kellen/The Petrie Museum of Egyptian Archaeology, University College London)

Metropolitan Museum curator of Egyptian Art Adela Oppenheim argues that it’s important to distinguish the archaicizing tendency of Egyptian culture from the real or apparent continuity of Egyptian civilization. Which is to say, the statue of Mentuhotep II doesn’t look old by Egyptian standards because no new ideas had intervened between the 3rd and the 11th dynasties, but because it was deliberately created to look old, a bit of propaganda meant to establish legitimacy and connection to the Old Kingdom.

And yet, for all of the self-conscious efforts of Middle Kingdom artisans to reference the revered Old Kingdom, the exhibition is focused more on change, some of it radical. By the late 12th dynasty, Middle Kingdom rulers were depicted with faces that show signs of aging, care and unrest. Their bodies are still young and athletic, but figures such as Senwosret III no longer have the smooth, rounded faces of indeterminate youth, and the benign half-smiles of the idealized depictions of earlier rulers. There is a gentle sag to the flesh around his mouth, a hollowness under the eyes, which droop slightly, and a small crease in the skin of his forehead. This is, as Met curator emeritus Dorothea Arnold argues in a catalogue essay, a truly astonishing development, resulting in “royal images among the most significant representations of human beings ever created.”

And yet, what does it mean? Is it a genuine portrait of an aging ruler? Or are these markers of age merely symbols of some newly cherished aspect of royal power, such as wisdom, or attentiveness or introspection? In any case, it’s remarkable to see the emergence of something new so clearly manifest, and to see it emerge from within what was presumably a tightly controlled practice of depicting the pharaoh, with a long tradition devoted to idealized depictions of power.

Among the other remarkable cultural shifts is a trend that appears to our eyes, in the 21st century, like a democratization of culture. Non-royal figures began to be buried with objects, texts and images that were once exclusive to the king, though this may reflect particular changes in religious practice — perhaps a centralization of customs — more than a fundamental shift in how different classes were enfranchised in the elaborate culture of death and rebirth that governed Egyptian life.

The exhibition nevertheless provides a rich sense of quotidian life, within and beyond the inner circle of the king. It includes musical instruments and games, models of boats and houses, and military ration tokens, presumably shown by a soldier to gain his allotment of bread. It also includes tools, a hand-held chisel and wooden mallet of the sort that would have been used to carve the finished pieces seen in the exhibition. Among the most striking works on view is an unfinished statuette, with the tracing line of a standing, crowned figure still clearly visible on the small limestone block.

This last piece can’t compare with the beauty on display in finished work, jewelry and cosmetic jars, wooden figurines and ornately finished reliefs and stelae. But it does capture the process of life — the fluid uncertainty of it — with remarkable power. The Middle Kingdom is a 19th-century idea, imposed on a dynamic period of Egyptian culture more for scholarly convenience than explanatory power. But “Ancient Egypt Transformed” manages the difficult process of capturing a culture in flux, without bookends, and without the convenient fiction that ancient Egypt was any more enslaved to its past than any other culture that seeks stability through precedent and the aggrandizement of history.

Ancient Egypt Transformed On view through Jan. 24 at the Metropolitan Museum of Art in New York . For more information, visit .