Sneferu becomes king (early Fourth Dynasty), launching an era of intensive royal building. His reign is commonly placed in the early 26th century BCE, with differing scholarly chronologies; many modern histories cite 2613–2589 BCE (Shaw chronology) for his reign.
Work at Meidum proceeds through multiple architectural phases (often labeled E1–E3): an initial step pyramid, subsequent enlargement, and then an attempt to convert it into a smooth-sided form by filling/encasing the steps—an important experimental stage in pyramid evolution.
In its later phase, the Meidum project is transformed from a stepped design toward a “true” pyramid by adding limestone casing that filled in the steps, reflecting a major technological and design transition leading into Sneferu’s Dahshur projects.
The Meidum pyramid’s outer casing and much of its fill collapsed in antiquity, leaving the tower-like core visible today. The precise timing of the collapse is debated, but it is widely accepted that major failure occurred long ago and that construction choices (including outer layers on sand) contributed to instability.
Sneferu’s major building program shifts to Dahshur, where two large pyramids (Bent and Red/North) were built and where experimentation culminated in a successfully completed smooth-sided pyramid tradition.
Construction of the Bent Pyramid at Dahshur begins with a steep lower slope (commonly reported around the low-to-mid 50° range). The project represents a major step toward smooth-sided pyramids, but revealed engineering limits as construction rose.
Partway up, the Bent Pyramid’s slope is changed to a shallower angle (reported around 43° in many summaries), producing its distinctive profile. Explanations vary, but sources commonly link the change to concerns about stability as builders gained experience with smooth-sided forms.
The Bent Pyramid is finished and is notable among Old Kingdom royal pyramids for having two entrances (on different faces), a feature that distinguishes it from most earlier and later pyramids and provides key evidence for evolving internal planning.
Sneferu initiates a second major Dahshur pyramid project—the Red Pyramid (also called the North Pyramid)—built at the lower slope angle associated with the Bent Pyramid’s upper section, reflecting a deliberate move toward a fully stable smooth-sided design.
The Red Pyramid is completed as Egypt’s first successfully finished smooth-sided (“true”) pyramid, establishing the mature form later used at Giza. It demonstrates the consolidation of design lessons learned at Meidum and the Bent Pyramid.
Sneferu’s projects—Meidum, Bent, and Red—collectively document a rapid progression from stepped massing and risky casing strategies to stable, repeatable smooth-sided pyramid engineering, setting the stage for Khufu’s later monumental work at Giza.
Sneferu’s reign ends (often given as 2589 BCE in Shaw-based chronologies). His building program left multiple large pyramid complexes and a proven architectural template that defined royal funerary construction for the remainder of the Fourth Dynasty.
Michael CarricoSneferu's pyramid projects: Meidum, Bent, and Red Pyramids (c. 2613–2589 BCE)