There is evidence of rock carvings along the Nile terraces and in desert oases. In the 10th millennium BCE, a culture of hunter-gatherers and fishers was replaced by a grain-grinding culture. Climate changes or overgrazing around 8000 BCE began to desiccate the pastoral lands of Egypt, forming the Sahara. Early tribal peoples migrated to the Nile River where they developed a settled agricultural economy and more centralised society.[41] By about 6000 BCE, a Neolithic culture took root in the Nile Valley.[42] During the Neolithic era, several predynastic cultures developed independently in Upper and Lower Egypt. The Badarian culture and the successor Naqada series are generally regarded as precursors to dynastic Egypt. The earliest known Lower Egyptian site, Merimda, predates the Badarian by about seven hundred years. Contemporaneous Lower Egyptian communities coexisted with their southern counterparts for more than two thousand years, remaining culturally distinct, but maintaining frequent contact through trade. The earliest known evidence of Egyptian hieroglyphic inscriptions appeared during the predynastic period on Naqada III pottery vessels, dated to about 3200 BCE.[43] The Giza Necropolis is the oldest of the ancient Wonders and the only one still in existence. A unified kingdom was founded c. 3150 BCE by King Menes, leading to a series of dynasties that ruled Egypt for the next three millennia. Egyptian culture flourished during this long period and remained distinctively Egyptian in its religion, arts, language and customs. The first two ruling dynasties of a unified Egypt set the stage for the Old Kingdom period, c. 2700–2200 BCE, which constructed many pyramids, most notably the Third Dynasty pyramid of Djoser and the Fourth Dynasty Giza pyramids. The First Intermediate Period ushered in a time of political upheaval for about 150 years.[44] Stronger Nile floods and stabilisation of government, however, brought back renewed prosperity for the country in the Middle Kingdom c. 2040 BCE, reaching a peak during the reign of Pharaoh Amenemhat III. A second period of disunity heralded the arrival of the first foreign ruling dynasty in Egypt, that of the Semitic Hyksos. The Hyksos invaders took over much of Lower Egypt around 1650 BCE and founded a new capital at Avaris. They were driven out by an Upper Egyptian force led by Ahmose I, who founded the Eighteenth Dynasty and relocated the capital from Memphis to Thebes. The New Kingdom c. 1550–1070 BCE began with the Eighteenth Dynasty, marking the rise of Egypt as an international power that expanded during its greatest extension to an empire as far south as Tombos in Nubia, and included parts of the Levant in the east. This period is noted for some of the most well known Pharaohs, including Hatshepsut, Thutmose III, Akhenaten and his wife Nefertiti, Tutankhamun and Ramesses II. The first historically attested expression of monotheism came during this period as Atenism. Frequent contacts with other nations brought new ideas to the New Kingdom. The country was later invaded and conquered by Libyans, Nubians and Assyrians, but native Egyptians eventually drove them out and regained control of their country.[45] The Weighing of the Heart from the Book of the Dead of Ani In 525 BCE, the Achaemenid Empire, led by Cambyses II, began their conquest of Egypt, eventually capturing the pharaoh Psamtik III at the battle of Pelusium. Cambyses II then assumed the formal title of pharaoh, but ruled Egypt from his home of Susa in Persia (modern Iran), leaving Egypt under the control of a satrapy. The entire Twenty-seventh Dynasty of Egypt, from 525 to 402 BCE, save for Petubastis III, was an entirely Achaemenid-ruled period, with the Achaemenid emperors all being granted the title of pharaoh. A few temporarily successful revolts against the Achaemenids marked the fifth century BCE, but Egypt was never able to permanently overthrow the Achaemenids.[46] The Thirtieth Dynasty was the last native ruling dynasty during the Pharaonic epoch. It fell to the Achaemenids again in 343 BCE after the last native Pharaoh, King Nectanebo II, was defeated in battle. This Thirty-first Dynasty of Egypt, however, did not last long, as the Achaemenids were toppled several decades later by Alexander the Great. The Macedonian Greek general of Alexander, Ptolemy I Soter, founded the Ptolemaic dynasty.[47] Ptolemaic and Roman Egypt Main articles: Ptolemaic Kingdom and Roman Egypt The Ptolemaic Queen Cleopatra VII and her son by Julius Caesar, Caesarion, at the Temple of Dendera The Ptolemaic Kingdom was a powerful Hellenistic state, extending from southern Syria in the east, to Cyrene to the west, and south to the frontier with Nubia. Alexandria became the capital city and a centre of Greek culture and trade. To gain recognition by the native Egyptian populace, they named themselves as the successors to the Pharaohs. The later Ptolemies took on Egyptian traditions, had themselves portrayed on public monuments in Egyptian style and dress, and participated in Egyptian religious life.[48][49] The last ruler from the Ptolemaic line was Cleopatra VII, who committed suicide following the burial of her lover Mark Antony, after Octavian had captured Alexandria and her mercenary forces had fled. The Ptolemies faced rebellions of native Egyptians and were involved in foreign and civil wars that led to the decline of the kingdom and its annexation by Rome. Christianity was brought to Egypt by Saint Mark the Evangelist in the 1st century.[50] Diocletian's reign (284–305 CE) marked the transition from the Roman to the Byzantine era in Egypt, when a great number of Egyptian Christians were persecuted. The New Testament had by then been translated into Egyptian. After the Council of Chalcedon in CE 451, a distinct Egyptian Coptic Church was firmly established.[51] Middle Ages (7th century – 1517) Main article: Egypt in the Middle Ages The Amr ibn al-As mosque in Cairo, recognised as the oldest in Africa The Byzantines were able to regain control of the country after a brief Sasanid Persian invasion early in the 7th century amidst the Byzantine–Sasanian War of 602–628 during which they established a new short-lived province for ten years known as Sasanian Egypt, until 639–42, when Egypt was invaded and conquered by the Islamic caliphate by the Muslim Arabs. When they defeated the Byzantine armies in Egypt, the Arabs brought Islam to the country. Some time during this period, Egyptians began to blend in their new faith with indigenous beliefs and practices, leading to various Sufi orders that have flourished to this day.[50] These earlier rites had survived the period of Coptic Christianity.[52] In 639 an army was sent in Egypt by the second caliph, Umar, under the command of Amr ibn al-As. They defeated a Roman army at the battle of Heliopolis. Amr next proceeded in the direction of Alexandria, which surrendered to him by a treaty signed on 8 November 641. Alexandria was regained for the Byzantine Empire in 645 but was retaken by Amr in 646. In 654 an invasion fleet sent by Constans II was repulsed. The Arabs founded the capital of Egypt called Fustat, which was later burned down during the Crusades. Cairo was later built in the year 969 to grow to become the largest and richest city in the Arab caliphate, second only to Baghdad.