Nynetjer (also known as Ninetjer and Banetjer) is the Horus name of the third early Egyptian king during the 2nd dynasty. The exact length of his reign is unknown. The Turin Canon suggests an improbable reign of 96 years and Egyptian historian Manetho suggested that Nynetjer's reign lasted 47 years. Egyptologists question both statements as misinterpretations or exaggerations. They generally credit Nynetjer with a reign of either 43 years or 45 years. Their estimation is based on the reconstructions of the well known Palermo Stone inscription reporting the years 7–21, the Cairo Stone inscription reporting the years 36–44. According to different authors, Nynetjer ruled Egypt from c. 2850 BC to 2760 BC or later from c. 2760 BC to 2715 BC.
Nynetjer is one of the best archaeologically attested kings of 2nd dynasty. His name appears in inscriptions on stone vessels and clay sealings in large numbers from his tomb at Sakkara. A large number of artifacts bearing his name were also found in the tomb of king Peribsen at Abydos and in the galleries beneath the step pyramid of king Djoser. However, the datings of some inscriptions, especially those made of black ink, caused some problems. Writing experts and archaeologists such as Ilona Regulski point out that the ink inscriptions are of a somewhat later date than the stone and seal inscriptions. She dates the ink markings to the reigns of kings such as Khasekhemwy and Djoser and assumes that the artifacts originated from Abydos. In fact, alabaster vessels and earthen jars with black ink inscriptions with very similar font design showing Nynetjer's name were found in Peribsen's tomb.