The founder of the first Macedonian empire, Philip II, had been opposed in Greece by Persia, but the resistance he had encountered because of the diplomacy of Artaxerxes Ochus was as nothing when compared with the difficulties raised up for Antigonus Gonatas's uncle, Cassander, by the promises and armies of his grandfather, Antigonus I, or with the obstacles he himself had to meet in the intrigue, money, and expeditions of Ptolemy Philadelphus. The situation which existed in the first ten years of his reign (277-267 B.C.) was not of Antigonus's creating, nor was Philadelphus responsible for it. It was Ptolemy I Soter who had seized the dominion of the sea on the final _débâcle_ of Demetrius Poliorcetes (287-286 B.C.) and with it the control of the league of the Islanders. This established a long and, in fact, indefinable frontier between the realm of Philadelphus and that of Antigonus. The lordship of the sea Gonatas seems not to have bothered about at first, and, indeed, the great war which broke out in 266-265 B.C. between the two monarchs--the so-called Chremonidean War--was clearly incited by Egypt and not by him. Notwithstanding that she was dead four years when the actual conflict began, its real instigator was, doubtless, Arsinoë, the sister-queen of Philadelphus. Acting on her policy, Philadelphus first formed an alliance with King Areus I of Sparta and his allies (Achæa, Elis, Mantinea, Phlius, and part of Crete) and with Athens, and then backed them up in the concerted effort they decided to make to free Greece from Antigonus and his "tyrants." What the real object of the "brother-gods" was, is a matter of conjecture. All they accomplished, in any case, was to give Antigonus five years of hard fighting[123] and to complete the ruin of Athens and the enforced quietude of Sparta.