Palermo Stone: 5 first years on PS and last 4 years on CF1 (?).

Manetho:

  Africanus: 29 years

  Eusebius: mentions this king, but does not record the length of his reign

Netjerikhet (Djoser) is the most famous king of the 3rd Dynasty. Through contemporary sources, he is only known by his Horus- and Nebti-names, Netjerikhet, "the divine of body". Later sources, among which a New Kingdom reference on his Step Pyramid at Saqqara, confirm that the Netjerikhet from the king lists and the builder of the Step Pyramid, Netjerikhet are one and the same.

According to the Turin King-list, Netjerikhet ruled for about 19 years, following the 20 year long reign of the otherwise unattested Nebka. Archaeological sources, however, have shown that he must be considered as the first king after Khasekhemwi, the last king of the 2nd Dynasty. The order by which some predecessors of Kheops are mentioned on the Papyrus Westcar may confirm that Nebka must be placed between Netjerikhet and Huni and not before. The fact that the Turin King-list has noted Netjerikhet's name in red may also be significant.

In view of Netjerikhet's building projects, particularly at Saqqara, the number of years credited to him by the Turin King-list has been doubted as well. It is not unlikely that the Turin King-list has mistaken bi-annual cattle-counts for years. If this is indeed the case, then Netjerikhet may have ruled up to 37 or 38 years.

Queen Nimaathapu, the wife of Khasekhemwi, is known to have held the title "Mother of the King". This makes it likely that Netjerikhetwas her son, with Khasekhemwi his father.

Three royal women are known from during his reign: Hetephernebti, Inetkawes, and a third one whose name is destroyed. Hetephernebti held the title "The one who may behold the Horus", indicating that she was Netjerikhet's (principal) queen. Inetkawes was a "Daughter of the King" and as at least one document shows her alongside Hetephernebti, it is likely that she was the latter's daughter.

The relationship between Netjerikhet and his successor, Sekhemkhet is not known, as Sekhemkhet's mother Batirites does not appear to have been mentionned alongside Netjerikhet.
 

Head of a lifesize statue of Netjerikhet, found in the Serdab of his mortuary complex at Saqqara (more...).

Some fragmentary reliefs found at Heliopolis and Gebelein mention Netjerikhet’s name and are an indication of Netjerikhet’s building policy. 

An inscription claiming to date to the reign of Netjerikhet, but actually created during the Ptolemaic Dynasty, relates how this king rebuilt the temple of the god Khnum on the island of Elephantine at the First Cataract and thus ended a famine in Egypt. Although this inscription is but a story, it does show that more than two millennia after his reign, Netjerikhet was still remembered on Elephantine. This at the very least indicates that he had a special status on that island. 

It is possible that during Netjerikhet’s reign, the country’s southern border was fixed at the First Cataract. 

Netjerikhet’s foreign policy was one of careful establishment of Egyptian presence in economically important places. He sent several military expeditions to the Sinai, during which the local Bedouin were overthrown. The Sinai owed its importance to the Egyptian economy for its valuable minerals turquoise and copper. It was also strategically important as a buffer between the Asian Bedouin and the Nile valley. 

Netjerikhet is mostly known for having commissioned the building of the Step Pyramid at Saqqara and its surrounding complex. His name is linked with that of the architect who planned and constructed the first stone buildings in the world, the high-priest and vizier Imhotep, who also built the Step Pyramid of Netjerikhet’s successor, Sekhemkhet. Besides the technological advances and the Ancient Egyptian craftsmenship, the building of Netjerikhet's funerary complex at Saqqara also demonstrates the organisational skills of the central government.
 

A fragment from Heliopolis shows part of the name of Netjerikhet in a Serekh.

A view on the Step Pyramid and part of the surrounding complex built for Netjerikhet at Saqqara.