The expulsion of the Hyksos by Ahmose marks the beginning of the 18th Dynasty, the first of the New Kingdom. It was a period in which Egypt would become a world power. As early as under Ahmose, expeditions to western Asia and Nubia were undertaken. Amenhotep I pushed Egypt's southern border much further south into Nubia. During his reign, cultural aspects began once again to flourish. An important text from his reign is the Ebers Papyrus, which not only tells us a great deal about medical knowledge but also contains the date of a heliacal rising of Sothis, an aid in determining the chronology of ancient Egypt. Tuthmosis I significantly expanded the empire with campaigns as far as the 5th Cataract in Nubia and across the Euphrates in Asia. After the short rule of Tuthmosis II, Tuthmosis III succeeded to the throne, with Hatshepsut functioning as regent. Later she appropiated the titulary of a pharaoh, and ruled alongside Tuthmosis until her death. As the sole ruler, he undertook various successful campaigns in Asia to conquer the various tribes there and penetrated as far as the Euphrates. Other expeditions to Syria were led by Amenhotep II and Tuthmosis IV. Parts of the region were steadily being lost to Egypt, however, and under Tuthmosis IV a peace treaty was signed with Mitanni. Tuthmosis IV was promised in a dream comparable to an oracle that he would become king if he freed the Sphinx of Giza from the sand. During the long and peaceful reign of Amenhotep III, Egypt experienced a period of unheard-of prosperity. His son Amenhotep IV proclaimed the Aten as the only god and banned the cults of all other gods, particularly that of Amun. Later, Amenhotep IV changed his name to Akhenaten and moved the residence to Akhetaten. Works of art with a particular style, called the Amarna style after the modern name for the area, were created during this period. In Asia, the Hittites conquered Syria and the Kingdom of Mitanni fell. Various Egyptian vassals transferred their loyalty to the Hittites. In El-`Amarna, an extensive correspondence between the Egyptian court and the various states in western Asia has been found, written in cuneiform. After the short reign of Semenkhkare, Tutankhamun ascended the throne, probably as a result of the influence of the general Horemheb. During his nine-year reign, the religious situation from before Amenhotep IV was restored and Akhetaten abandoned as the residence. General Horemheb had control of the armies and, after the short reign of Ay, would rule himself as the last pharaoh of the 18th Dynasty. Later tradition regarded him as the successor to Amenhotep III, ignoring his four predecessors, all of whom were linked with the Amarna period. Under Horemheb, Paramessu, later King Ramesses I (19th Dynasty), became general of the army.