Den, also known as Hor-Den, Dewen, and Udimu, was the Horus name of a pharaoh of the Early Dynastic Period who ruled during the First Dynasty of Egypt. He is the best archaeologically-attested ruler of this period, credited with bringing prosperity to his realm.
Den was the first to use the title "King of Upper and Lower Egypt" and the first depicted as wearing the double crown (red and white). Notably, the floor of his tomb at Umm El Qa'ab, near Abydos, was constructed using red and black granite, making it the earliest known use of this hard stone as a building material in Egypt with a flight of stairs leading to it. During his long reign, he established many of the customs of court ritual and royalty drawn on by later rulers and was held in high regard by his immediate successors.
The Ancient Egyptian historian Manetho called him “Oúsaphaîdos” and credited him with a reign of 20 years, whilst the Royal Canon of Turin is damaged and therefore unable to provide information about the duration of Den's reign. Egyptologists and historians generally believe that Den had a reign of 42 years, based on inscriptions on the Palermo Stone.
Recent radiocarbon data from the tombs at Abu Rawash, datable to the reign of Den, provide likely estimate for the Den's accession to 3011–2921 BCE (1σ).
Den's serekh name is well attested on earthen seal impressions, on ivory labels and in inscriptions on vessels made of schist, diorite and marble. The artifacts were found at Abydos, Saqqara and Abu Rawash. Den's name is also attested in later documents. For example, the Medical Papyrus of Berlin (the Ramesside era) discusses several methods of treatment and therapies for a number of different diseases. Some of these methods are said to originate from the reign of Den, but this statement may merely be trying to make the medical advice sound traditional and authoritative. Similarly, Den is mentioned in the Papyrus of Ani (also dated to Ramesside times) in chapter 64.
Den's serekh name was "Den" or "Dewen", most likely meaning "he who brings the water".