From the beginning of the Dynastic Era (2950 B.C.), royal tombs were carved into rock and covered with flat-roofed rectangular structures known as “mastabas,” which were precursors to the pyramids. The oldest known pyramid in Egypt was built around 2630 B.C. at Saqqara, for the third dynasty’s King Djoser. Known as the Step Pyramid, it began as a traditional mastaba but grew into something much more ambitious. As the story goes, the pyramid’s architect was Imhotep, a priest and healer who some 1,400 years later would be deified as the patron saint of scribes and physicians. Over the course of Djoser’s nearly 20-year reign, pyramid builders assembled six stepped layers…