The pyramids of Ancient Egypt went through many changes before they took on the geometric shape that we are accustomed to seeing. Egyptian tombs originally began as a simple pit in the sandy desert that was lined with a reed mat. Pharaohs and commoners were buried in the same fashion. As Egyptian religious beliefs developed, pharaohs were buried with artifacts that were necessary in the afterlife. Due to vandalism, and the increasing number of artifacts that were buried with wealthy kings, the pit became a rectangular hole lined with mud bricks or timber. A mound was created over the burial site, which was supported by timber poles and covered with bricks. These covered mounds were known as mastabas.
Over the years, the interior of mastabas became increasingly elaborate with the intention of confusing tomb robbers, and to allow more room to hold a pharaoh's possessions for the afterlife. The tunnel that accessed the sunken burial chamber was filled with sand, rubble, and stone barriers. The entrance was then disguised to look like part of the wall. Portraits of servants would be painted on the interior walls to serve their master his afterlife. Tombs for a pharaoh's servants were constructed around the King's mastaba for the same reason. Beginning in 3,200 B.C., the exterior of a King's mastaba was decorated with ornate brickwork imitating timber and reed matting. Though extensive measures were taken, these tombs were often robbed, because the design was common among all mastabas.
With the conclusion of Zoser's reign, the mastaba underwent more developments. Stone replaced mud brick in construction, and two false doorways were added to the eastern face for the use of the pharaoh's ba, meaning soul. An inner room of the mastaba, called the serdab, was used to house a statue of the buried king that could house the ba if the body was disturbed for any reason. A narrow slit in the far wall of the serdab allowed the ba access to the outside world. As an extra precaution, the pharaoh's name was carved into the base of the statue in case it was destroyed.
The first Egyptian pyramid was created for King Zoser by the architect Imhotep. The concept of the stone mastaba was transformed into a four level tomb consisting of stacked mastabas that decreased in size as they reached the peak. The steps that the pyramid formed were believed to act as a ladder that the dead king took to reach the gods. In Zoser's pyramid, the burial chamber was located at the bottom of a 92 ft. shaft. The chamber entrance could be reached by travelling down a sloping passage originating at the north face. A series of Gallery Rooms were located at the bottom of the shaft, and led into the King's burial chamber which was lined with timber and blue tiles. The serdab and offering chapels were in a temple on the north face of the pyramid that contained two open courtyards, several chapels, and storerooms. The temple was roofed with stone slabs that were carved and painted to represent the earlier palm-trunk ceilings.
After the creation of the first step-pyramids, the design was modified to have smooth, limestone faces. The steps of the inner pyramid were covered in hand-chiseled limestone taken from the quarries of Aswan farther down the Nile River. The appearance in the day of the Ancient Egyptians was that of a shimmering white mountain. The inspiration for sloping the sides of the pyramids came from an image formed by the sun's rays breaking through the clouds. It was intended to bring the buried pharoah closer to the sun god Re.
The first true pyramid was constructed for King Snefru at Medium. The burial chamber was only accessible by a small tunnel in the north face with a 28 degree slope. The famous bent pyramid at Dahshur has sides that originally sloped at 54 degrees. Midway through the project, cracks began to appear due to the steep slope. From this point on, architects changed the slope to a gentler 43 degrees, which became the standard for all pyramids.
1. Edwards, I.E.S. "Pyramids: Building for Eternity - Ancient Egypt: Discovering its Splendors" National Geographic Society