Empire of Alexander the Great in the context of "Ancient Greek science"

The Ptolemaic Kingdom (/ˌtɒlɪˈmeɪ.ɪk/; Koine Greek: Πτολεμαϊκὴ βασιλεία, Ptolemaïkḕ basileía) or Ptolemaic Empire was an ancient Greek polity based in Egypt during the Hellenistic period. It was founded in 305 BC by the Macedonian Greek general Ptolemy I Soter, a companion of Alexander the Great, and ruled by the Ptolemaic dynasty until the death of Cleopatra VII in 30 BC. Reigning for nearly three centuries, the Ptolemies were the longest and final dynasty of ancient Egypt, heralding a distinct era of religious and cultural syncretism between Greek and Egyptian culture.

Alexander the Great conquered Egypt in 332 BC during his campaigns against the Achaemenid Empire. Alexander's death in 323 BC was followed by the rapid unraveling of the Macedonian Empire amid competing claims by the diadochi, his closest friends and companions. Ptolemy, one of Alexander's most trusted generals and confidants, won control of Egypt from his rivals and declared himself its ruler in 305 BC. Alexandria, a Greek polis founded by Alexander, became the capital city and a major center of Greek culture, learning, and trade for the next several centuries. Following the Syrian Wars with the Seleucid Empire, a rival Hellenistic state, the Ptolemaic Kingdom expanded its territory to include eastern Libya, the Sinai, and northern Nubia.

Antigonus I Monophthalmus (Ancient Greek: Ἀντίγονος Μονόφθαλμος Antigonos Monophthalmos, "Antigonus the One-Eyed"; 382 – 301 BC) was a Macedonian Greek general and successor of Alexander the Great. A prominent military leader in Alexander's army, he went on to control large parts of Alexander's former empire. He assumed the title of basileus (king) in 306 BC and reigned until his death. He was the founder of the Antigonid dynasty, which ruled over Macedonia until its conquest by the Roman Republic in 168 BC.

Antigonus likely served under Philip II of Macedon. He took part in Alexander's invasion of Achaemenid Persia and was named satrap of Phrygia. After Alexander's death in 323 BC, he also received Pamphylia and Lycia in accordance with the Partition of Babylon. However, he later incurred the enmity of Perdiccas, the regent of Alexander's empire, and was driven from Phrygia. He fled to Greece and formed an alliance with Antipater, later joined by Ptolemy, against Perdiccas. Perdiccas was murdered by his own officers in 320 BC, and Antipater was elected the new regent. During a series of wars between Alexander's successors, Antigonus briefly emerged as the most powerful of the Diadochi, ruling over Greece, Asia Minor, Syria, Phoenicia and northern Mesopotamia. Cassander, Seleucus, Ptolemy and Lysimachus formed a coalition against him, which culminated in his decisive defeat and death at the Battle of Ipsus in 301 BC. His kingdom was divided up by Lysimachus and Seleucus, but his son Demetrius survived and went on to seize control of Macedonia in 294 BC.

Alexander the Great (356 – 323 BC), a king of ancient Macedon, created one of the largest empires in history by waging an extensive military campaign throughout Asia. Alexander was groomed for rulership from an early age and acceded to the throne after the assassination of his father, Philip II. After subduing rebellious vassals, he invaded the Persian Achaemenid Empire in 334 BC. Alexander swiftly conquered large areas of Western Asia and Egypt before defeating the Persian king Darius III in battle at Issus and Gaugamela. Achieving complete domination over the former lands of the Achaemenids by 327 BC, Alexander attempted to conquer India but turned back after his weary troops mutinied. Following his death aged thirty-two in Babylon in 323 BC, his empire disintegrated in a series of civil wars fought between his followers.

Alexander founded numerous settlements during his campaigns, naming them after himself or close followers. These have been the subject of intense debate, as the accounts of ancient and medieval scholars differ wildly and are often contradictory. Plutarch provides the maximum estimate of seventy cities in his Life of Alexander, but most texts attest to between ten and twenty foundations. The Greek Alexander Romance lists between nine and thirteen cities, depending on the recension; the Syriac, Armenian, Hebrew, and Ethiopic versions of the Romance also record twelve or thirteen foundations. Persian sources such as al-Tabari, al-Dinawari, Hamza al-Isfahani, and Qudama ascribe between nine and twelve settlements to Alexander. Stephanus of Byzantium recorded around twenty settlements. Some authors additionally document the number of cities established in a specific area: for example, Strabo records that Alexander founded eight cities in Bactria. The accounts of Alexander's campaigns, primarily those of Arrian, Plutarch, Diodorus, Curtius Rufus, and Justin, provide supplementary evidence. Finally, the geographers Eratosthenes, Ptolemy, and Pliny draw upon the otherwise-lost evidence of Alexander's bematist distance-measurers.