In 306, Antigonus attempted to invade Egypt, but storms prevented Demetrius' fleet from supplying him, and he was forced to return home. Now, with Cassander and Ptolemy both weakened, and Seleucus still occupied in the East, Antigonus and Demetrius turned their attention to Rhodes, which was besieged by Demetrius's forces in 305 BC. The island was reinforced by troops from Ptolemy, Lysimachus, and Cassander. Ultimately, the Rhodians reached a compromise with Demetrius – they would support Antigonus and Demetrius against all enemies, save their great ally Ptolemy. Ptolemy took the title of "Soter" ("Savior") for his role in preventing the fall of Rhodes, but the victory was ultimately Demetrius', as it left him with a free hand to attack Cassander in Greece. Demetrius returned to Greece, defeated Cassander, and formed a new Hellenic League, with himself as general, to defend the Greek cities against all enemies (and particularly Cassander).