This abominable act, however, does not appear to have caused a breach of the peace. Ptolemy was the first to break it (B.C. 310), under the pretext that Antigonus, by keeping his garrisons in the Greek cities of Asia and the islands, had not respected that article of the treaty which guaranteed Grecian freedom. After the war had lasted three years Antigonus resolved to make a vigorous effort to wrest Greece from the hands of Cassander and Ptolemy, who held all the principal towns in it. Accordingly, in the summer of 307 B.C. he despatched his son Demetrius from Ephesus to Athens, with a fleet of 250 sail, and 5000 talents in money. Demetrius, who afterwards obtained the surname of "Poliorcetes," or "Besieger of Cities," was a young man of ardent temperament and great abilities. Upon arriving at the Piraeus he immediately proclaimed the object of his expedition to be the liberation of Athens and the expulsion of the Macedonian garrison. Supported by the Macedonians, Demetrius the Phalerean had now ruled Athens for a period of more than ten years. Of mean birth, Demetrius the Phalerean owed his elevation entirely to his talents and perseverance. His skill as an orator raised him to distinction among his countrymen; and his politics, which led him to embrace the party of Phocion, recommended him to Cassander and the Macedonians. He cultivated many branches of literature, and was at once an historian, a philosopher, and a poet; but none of his works have come down to us. The Athenians heard with pleasure the proclamations of the son of Antigonus his namesake, the Phalerean was obliged to surrender the city to him, and to close his political career by retiring to Thebes. The Macedonian garrison in Munychia offered a slight resistance, which was soon overcome, Demetrius Poliorcetes then formally announced to the Athenian assembly the restoration of their ancient constitution, and promised them a large donative of corn and ship-timber. This munificence was repaid by the Athenians with the basest and most abject flattery. Both Demetrius and his father were deified, and two new tribes, those of Antigonias and Demetrias, were added to the existing ten which derived their names from the ancient heroes of Attica. Demetrius Poliorcetes did not, however, remain long at Athens. Early in 306 B.C. he was recalled by his father, and, sailing to Cyprus, undertook the siege of Salamis. Ptolemy hastened to its relief with 140 vessels and 10,000 troops. The battle that ensued was one of the most memorable 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.