The succession of Aha is somewhat problematic. Following Manetho and some king lists, it is ordinarily assumed that after Aha’s death, his son, Djer, known to Manetho as Athothis, became the new king. Some king lists, however, insert another, short reign of a king named Iti between Aha’s and Djer’s. The identification of this Iti is somewhat problematic. Djer’s mother was not Aha’s principal wife Neithhotep, but one of his lesser wives. Considering the archaeological evidence of that time, Neithhotep must have been a powerful and important lady, even during the reign of Aha. It is not impossible that for a short time following the death of Aha, she succeeded her husband, and that she in her turn would be succeeded by Djer. The rare contemporary sources from Djer’s reign inform us that he visited some Lower-Egyptian temples in Sais and Buto, and that he at least held one military expedition in Nubia, thus continuing the policy established by his father. A drawing on a wooden docket holds the hieroglyphs representing the South and the North, as well as Djer’s name. This indicates that during his reign, the Egyptian unity was a certain fact.
Djer’s eventual successor was Djet (sometimes called Wadji), but it is not unlikely that Djer’s daughter Merneith, following the example of Neithhotep, ruled the country for some time following her father's death. Although not proven, it is sometimes assumed that Merneith was Djet's wife. Other researches, however, postulate that she was Djet's mother or stepmother. Not much is known about either Merneith’s or Djet’s reigns, but a funerary stela from Abydos with Djet’s name, is one of the finest examples of Early-Dynastic Egyptian art.
Djet’s successor Den (sometimes called Dewen) is the first known to have used the title "King of Upper- and Lower-Egypt", a title that would soon become one of the most frequently used in the royal titulary. Den’s throne name, as the name following this title is called, was Semti. This name allows us to identify Den as the Hesepti from the king-lists and as Usaphaidos mentioned by Manetho. The first of a series of military campaigns against Asia took place as soon as Den's first year. An ivory label found in Abydos shows Den while slaying an enemy. The accompanying texts informs us that this label commemorates Den's first victory against the east, suggesting that it would not be his only one. Among the rich tributes he conquered in Asia appear to have been female prisoners who were sent to his hârim. Some of Den’s deeds are recorded on the Palermo Stone, though it is not certain that the described deeds relate to Den, since the name of the king mentioned on the Palermo Stone and usually identified as Den is missing. If the identification of the unnamed king of the Palermo Stone with Den is indeed correct, Den may have ruled for about 45 years. He also made some important internal reforms meant to counter the rising power of the governmental officials. That Den’s reign must have been quite prosperous, is also shown by the many private tombs dated to that period, that are often considered as the most beautiful of that period. He was praised by his immediate successors as well as by later generations until the Late-Dynastic Period as one of Egypt's most important kings.
A vessel found in Saqqara mentions the names of the three last kings of the 1st Dynasty: Anedjib, Semerkhet and Qa-a. There seem to have been dynastic troubles between Anedjib an Semerkhet: during the reign of Semerkhet, Anedjib’s name was removed from as many records as possible, a common practice usually indicating that the king who’s name was attacked had fallen from grace or that he was not considered as a legitimate king by his successors. On the other hand, Semerkhet’s name is not present in the king-lists and Manetho informs us that during Semerkhet’s reign, the country fell victim to disaster, yet another indication that Semerkhet’s rule may not have been legitimate. Again according to Manetho, Semerkhet’s rule lasted for 18 years, but the Palermo Stone only credits him for 9. This could mean that Semerkhet’s rule may have overlapped with either Anedjib’s or Qa-a’s. Qa-a may have considered Semerkhet as an usurper. Qa-a was the last Early-Dynastic king to have had a burial at the ancient cemetery of Abydos. After Qa-a's death, the political and religious centre of the country would shift to the north, to Memphis.