1911 Encyclopædia Britannica, Volume 20… (1911)
“ Alexander, who sided with his mother, withdrew, along with her, into Epirus, whence they both returned in the following year, after the assassination of Philip, which Olympias is said to have countenanced. During the absence of Alexander, with whom she regularly corresponded on public as well as domestic affairs, she had great influence, and by her arrogance and ambition caused such trouble to the regent Antipater that on Alexander’s death (323) she found it prudent to withdraw into Epirus. ”
