Buto - Edjo - Pe - Per Wadjet
The modern name Tell el-Farain means 'Mound of hte Pharaohs'. Situated in the northwestern Delta, some 95 km east of Alexandria, the ancient city of Buto has left traces of occupation from the Predynastic times into the Roman period. From textual material the location is identified as the semi-mythical twin capitals Pe and Dep of the Predynastic period. At the site are three mounds of which two showed town remains and the third a temple enclosure, which fits in with the idea of a twin-city.
Buto, or Pe, was the northern counterpart cult center in Lower Egypt to Nekhen (Hierakonpolis) in Upper Egypt, which was the southern one. These cult centers are believed to have acted as national shrines with a political function of unifying the two areas Upper and Lower Egypt. They are reflected in the hieroglyphs O18 and O20 from the Gardiner sign list, Per-wer for Nekhen and Upper Egypt and Per-nu for Buto and Lower Egypt. At first, the scarcity of finds from Buto led egyptologists to doubt the site had been peopled at all during the earlyiest times, and not until excavations since 1985 by the German Archaeological Institite in Cairo, have evidence been found from both the Predynastic, Early Dynastic and the early Old Kingdom period. The excavations were carried out under extremely difficult conditions far below the water table. The finds indicate that the Predynastic period here was replaced with the Naqada II/III culture of Upper Egypt, which supports the old theory that Lower Egypt at one point was subjugated by Upper Egypt, and that this might have led to the unufication of the Two Lands.
While the word Nekhen means 'city of the falcon', and several finds indicate that Horus, or an early form of Horus, was the cult deity here, the deity which was worshipped at Pe remains obscure as nothing has sofar been found of the earliest shrine. In the Book of Going Forth By Day, chapter 112, it is told that the Delta city of Pe was given to Horus as a compensation for Set injuring his eye, but as these texts are from the New Kingdom and only some spells go back to possibly the Middle Kingdom, we are not much helped. Is this tradition speaking or is it construction of a later date? On pure speculation until more evidence might surface, maybe we could play with the thought that Horus was the worshipped deity here too as well as at Nekhen, on the grounds that the King was considered the acclaimed personification of the 'Living Horus' which is indicated from his name being inscribed within the serekh surmounted with a falcon, and forthwith in the Pyramid Texts being referred to this epiteth. It was probably vital for him in order to keep the two lands of Upper and Lower Egypt together as one country under one ruler, to establish himself as the 'Living' ruler of both.
Buto has a second association as the name of Per-Wadjet indicates. This is the ancient center of the cobra goddess Wadjet, or Edjo, who functioned as a tutelary goddess to the king, together with the southern counterpart Nekhbet, the vulture goddess of Nekheb (el-Kab), situated on the opposite bank of the Nile from Nekhen. The name means 'she of Nekheb. The shrine of Wadjet, the Per-nu or Per-neser, meaning the 'house of flame', is attested from predynastic times, and at el-Kab the shrine of Nekhbet, the Per-wer, meaning 'the Great House', is attested by her possible presence at the Narmer macehead. Probably due to the close proximity of the capital city of Nekhen oppsite the Nile, her connection to the king made Nekhbet one of the tutelary goddesses together with Wadjet, and she came to symbolize the White Crown of Upper Egypt, while Wadjet at Buto symbolized the Red Crown of Lower Egypt.
How far back in time the origin of this concept reaches is uncertain but the first scriptual evidence of Nekhbet and Wadjet as tutelary mothers of the king, is to be found in the Pyramid Texts. Thus it must have held enough significance at the time to be included in these rituals, which purpose was to make safe the rebirth of the king in the Afterlife, and thus it is likely that the two goddesses go even further back in time. The symbolic importance of Buto in ancient times is more reflected in titulary and ceremony of kingship and the complementary character of the two lands Upper and Lower Egypt, as it comes down to us in texts and mythology, than in finds from the area.
The concept of the ancestor spirits, the so called 'Souls of Nekhen and Pe' originated in these early periods and lasted throughout Egyptian history. Read more about them here.
Sources:
Early Dynastic Egypt - Toby A. Wilkinson
Chronicles of the Pharaohs - Peter A. Clayton
Cultural Atlas of Ancient Egypt - John Baines & Jaromir Malek