Perdiccas possessed more power than any of Alexander's generals, and he now aspired to the Macedonian throne. His designs, however, were not unknown to Antigonus and Ptolemy; and when he attempted to bring Antigonus to trial for some offence in the government of his satrapy, that general made his escape to Macedonia, where he revealed to Antipater the full extent of the ambitious schemes of Perdiccas, and thus at once induced Antipater and Craterus to unite in a league with him and Ptolemy, and openly declare war against the regent. Thus assailed on all sides, Perdiccas resolved to direct his arms in the first instance against Ptolemy. In the spring of B.C. 321 he accordingly set out on his march against Egypt, at the head of a formidable army, and accompanied by Philip Arrhidaeus, and Roxana and her infant son. He advanced without opposition as far as Pelusium, but he found the banks of the Nile strongly fortified and guarded by Ptolemy, and was repulsed in repeated attempts to force the passage of the river; in the last of which, near Memphis, he lost great numbers of men by the depth and rapidity of the current. Perdiccas had never been popular with the soldiery, and these disasters completely alienated their affections. A conspiracy was formed against him, and some of his chief officers murdered him in his tent. The death of Perdiccas was followed by a fresh distribution of the provinces of the empire. At a meeting of the generals held at Triparadisus in Syria, towards the end of the year 321 B.C., Antipater was declared regent, retaining the government of Macedonia and Greece; Ptolemy was continued in the government of Egypt; Seleucus received the satrapy of Babylon; whilst Antigonus not only retained his old province, but was rewarded with that of Susiana. Antipater did not long survive these events. He died in the year 318, at the advanced age of 80, leaving Polysperchon, one of Alexander's oldest generals, regent; much to the surprise and mortification of his son Cassander, who received only the secondary dignity of Chiliarch, or commander of the cavalry. Cassander was now bent on obtaining the regency; but seeing no hope of success in Macedonia, he went over to Asia to solicit the assistance of Antigonus.