Egypt reached the pinnacle of its power in the New Kingdom, ruling much of Nubia and a sizable portion of the Near East, after which it entered a period of slow decline. During the course of its history Egypt was invaded or conquered by a number of foreign powers, including the Hyksos, the Libyans, the Nubians, the Assyrians, the Achaemenid Persians, and the Macedonians under the command of Alexander the Great. The Greek Ptolemaic Kingdom, formed in the aftermath of Alexander's death, ruled Egypt until 30BC, when, under Cleopatra, it fell to the Roman Empire and became a Roman province.