in the annals of ancient naval warfare； more particularly on account of the vast size of the vessels engaged。 Ptolemy was completely defeated； and so important was the victory deemed by Antigonus； that on the strength of it he assumed the title of king； which he also conferred upon his son。 This example was followed by Ptolemy； Seleucus； and Lysimachus。
Demetrius now undertook an expedition against Rhodes； which had refused its aid in the attack upon Ptolemy。 It was from the memorable siege of Rhodes that Demetrius obtained his name of 〃Poliorcetes。〃 After in vain attempting to take the town from the sea…side； by means of floating batteries； from which stones of enormous weight were hurled from engines with incredible force against the walls； he determined to alter his plan and invest it on the land…side。 With the assistance of Epimachus； an Athenian engineer； he constructed a machine which； in anticipation of its effect； was called Helepolis； or 〃the city…taker。〃 This was a square wooden tower； 150 feet high； and divided into nine stories； filled with armed men； who discharged missiles through apertures in the sides。 When armed and prepared for attack； it required the strength of 2300 men to set this enormous machine in motion。 But though it was assisted by the operation of two battering…rams； each 150 feet long and propelled by the labour of 1000 men； the Rhodians were so active in repairing the breaches made in their walls； that； after a year spent in the vain attempt to take the town； Demetrius was forced to retire and grant the Rhodians peace。
In 301 B。C； the struggle between Antigonus and his rivals was brought to a close by the battle of Ipsus in Phrygia； in which Antigonus was killed； and his army completely defeated。 He had attained the age of 81 at the time of his death。 A third partition of the empire of Alexander was now made。 Seleucus and Lysimachus shared between them the possessions of Antigonus。 Lysimachus seems to have had the greater part of Asia Minor； whilst the whole country from the coast of Syria to the Euphrates； as well as a part of Phrygia and Cappadocia； fell to the share of Seleucus。 The latter founded on the Orontes a new capital of his empire； which he named Antioch； after his father Antiochus； and which long continued to be one of the most important Greek cities in Asia。 The fall of Antigonus secured Cassander in the possession of Greece。
Demetrius was now a fugitive； but in the following year he was agreeably surprised by receiving an embassy from Seleucus； by which that monarch solicited his daughter Stratonice in marriage。 Demetrius gladly granted the request； and found himself so much strengthened by this alliance； that in the spring of the year 296 he was in a condition to attack Athens； which he captured after a long siege； and drove out the bloodthirsty tyrant Lachares； who had been established there by Cassander。
Meanwhile Cassander had died shortly before the siege of Athens； and was succeeded on the throne of Macedon by his eldest son； Philip IV。 ＇Philip Arrhidaeus is called Philip III。＇ But that young prince died in 295； and the succession was disputed between his two brothers； Antipater and Alexander。 Demetrius availed himself of the distracted state of Macedonia to make himself master of that country （B。C。 294）。 He reigned over Macedonia； and the greater part of Greece； about seven years。 He aimed at recovering the whole of his father's dominions in Asia； but before he was ready to take the field； his adversaries； alarmed at his preparations； determined to forestall him。 In the spring of B。C。 287 Ptolemy sent a powerful fleet against Greece； while Pyrrhus on the one side and Lysimachus on the other simultaneously invaded Macedonia。 Demetrius had completely alienated his own subjects by his proud and haughty bearing； and by his lavish expenditure on his own luxuries； while Pyrrhus by his generosity； affability； and daring courage； had become the hero of the Macedonians； who looked upon him as a second Alexander。 The appearance of Pyrrhus was the signal for revolt： the Macedonian troops flocked to his standard and Demetrius was compelled to fly。 Pyrrhus now ascended the throne of Macedonia； but his reign was of brief duration； and at the end of seven months he was in turn driven out by Lysimachus。 Demetrius made several attempts to regain his power in Greece； and then set sail for Asia； where he successively endeavoured to establish himself in the territories of Lysimachus； and of his son…in…law Seleucus。 Falling at length into the hands of the latter； he was kept in a kind of magnificent captivity in a royal residence in Syria； where； in 283； at the early age of 55； his chequered career was brought to a close； partly by chagrin； and partly by the sensual indulgences with which be endeavoured to divert it。
Lysimachus； Seleucus； and Ptolemy now divided the empire of Alexander between them。 In Egypt the aged Ptolemy had abdicated in 285 in favour of his son by Berenice afterwards known as Ptolemy Philadelphus； and to the exclusion of his eldest son； Ptolemy Ceraunus； by his wife Eurydice。 Ptolemy Ceraunus quitted Egypt in disgust； and fled to the court of Lysimachus； and Arsinoe； the wife of Lysimachus； jealous of her stepson Agathocles； the heir apparent to the throne； and desirous of securing the succession for her own children； conspired with Ptolemy Ceraunus against the life of Agathocles。 She even procured the consent of Lysimachus to his murder； and after some vain attempts to make away with him by poison； he was flung into prison； where Ptolemy Ceraunus despatched him with his own hand。 Lysandra； the mother of Agathocles； fled with the rest of her family to Seleucus； to demand from him protection and vengeance； and Seleucus； induced by the hopes of success； inspired by the discontent and dissensions which so foul an act had excited among the subjects of Lysimachus； espoused her cause。 The hostilities which ensued between him and Lysimachus were brought to a termination by the battle of Corupedion； fought near Sardis in 281； in which Lysimachus was defeated and slain。 By this victory； Macedonia； and the whole of Alexander's empire； with the exception of Egypt； southern Syria； Cyprus； and part of Phoenicia； fell under the sceptre of Seleucus。
That monarch； who had not beheld his native land since he first joined the expedition of Alexander； now crossed the Hellespont to take possession of Macedonia。 Ptolemy Ceraunus； who after the battle of Corupedion had thrown himself on the mercy of Seleucus； and had been received with forgiveness and favour； accompanied him on this journey。 The murder of Agathocles had not been committed by Ptolemy merely to oblige Arsinoe。 He had even then designs upon the supreme power； which he now completed by another crime。 As Seleucus stopped to sacrifice at a celebrated altar near Lysimachia in Thrace； Ptolemy treacherously assassinated him by stabbing him in the back （280）。 After this base and cowardly act； Ptolemy Ceraunus； who gave himself out as the avenger of Lysimachus； was； by one of those movements wholly inexplicable to our modern notions； saluted king by the army； but the Asiatic dominions of Seleucus fell to his son Antiochus； surnamed Soter。 The crime of Ptolemy。 however； was speedily overtaken by a just punishment。 In the very same year his kingdom of Macedonia and Thrace was invaded by an immense host of Celts； and Ptolemy fell at the head of the forces which he led against them。 A second invasion of the same barbarians compelled the Greeks to raise a force for their defence； which was intrusted to the command of the Athenian Callippus （B。C。 279）。 On this occasion the Celts attracted by the report of treasures which were now perhaps little more than an empty name； penetrated as far southwards as Delphi； with the view of plundering the temple。 The god； it is said； vindicated his sanctuary on this occasion in the same supernatural manner as when it was attacked by the Persians： it is at all events certain that the Celts were repulsed with great loss； including that of their leader Brennus。 Nevertheless some of their tribes succeeded in establishing themselves near the Danube； others settled on the sea…coast of Thrace whilst a third portion passed over into Asia； and gave their name to the country called Galatia。
After the death of Ptolemy Ceraunus； Macedonia fell for some time into a state of anarchy and confusion； and the crown was disputed by several pretenders。 At length； in 278； Antigonus Gonatas； son of Demetrius Poliorcetes； succeeded in establishing himself on the throne of Macedonia； and； with the exception of two or three years （274…272） during which he was temporarily expelled by Pyrrhus； he continued to retain possession of it till his death in 239。 The struggle between Antigonus and Pyrrhus was brought to a close at Argos in 272。 Pyrrhus had marched into the Peloponnesus with a large force in order to make war upon Sparta； but with the collateral design of reducing the places which still held out for Antigonus。 Pyrrhus having failed in an attempt to take Sparta； marched against Argos； where Antigonus also arrived with his forces。 Both armies entered the city by opposite gates； an