The Second Dynasty of ancient Egypt (notated Dynasty II) is often combined with Dynasty I under the group title Early Dynastic Period. It dates approximately from 2890 to 2686 BC. The capital at that time was Thinis.

The names of the actual rulers of the Second Dynasty are in dispute. For the first five pharaohs, the sources are fairly close in agreement. Known rulers, in the History of Egypt, for this dynasty are as follows:

However, the identity of the next two or three rulers is unclear: we may have both the Horus-name or Nebty (meaning two ladies) -name and their birth names for these rulers; they may be entirely different individuals; or they may be legendary names. On the left are the rulers most Egyptologists place here; on the right are the names that ultimately come from Manetho's Aegyptica:

With the last ruler, we return to an agreement:

Although Manetho states the capital was at Thinis, the same as during the First Dynasty, at least the first three kings were buried at Saqqara, suggesting the center of power had moved to Memphis. Beyond this, little can be said about the events during this period; the annual records on the Palermo stone only survive for the end of the reign of Nebra and for parts of Nynetjer's. One important event possibly happened during the reign of Khasekhemwy: many Egyptologists read his name ("the Two Powers are Crowned") as commemorating the union of Upper and Lower Egypts.