Imhotep
As an architect, Imhotep was most famous because he was the designer of the step pyramid at Sakkara.  Before the step pyramid, pharaohs were buried in flat topped buildings called mastabas. The term mastaba comes from the word meaning bench, because they look like the benches most Egyptians placed outside their door. An average mastaba had four walls, a flat top and an underground burial chamber, reached by a vertical shaft or stairwell.The step pyramid was actually just a number of mastabas placed one on top of the other, each one smaller than the previous one.  There were also a couple of small rooms above the burial chambers with items for the afterlife.