Though they were influential, Pericles, Aspasia and their friends were not immune from attack, as preeminence in democratic Athens was not equivalent to absolute rule. Her relationship with Pericles and her subsequent political influence aroused many reactions. Donald Kagan, a Yale historian, believes that Aspasia was particularly unpopular in the years immediately following the Samian War. In 440 BC, Samos was at war with Miletus over Priene, an ancient city of Ionia in the foothills of Mycale. Worsted in the war, the Milesians came to Athens to plead their case against the Samians. When the Athenians ordered the two sides to stop fighting and submit the case to arbitration at Athens, the Samians refused. In response, Pericles passed a decree dispatching an expedition to Samos. The campaign proved to be difficult and the Athenians had to endure heavy casualties before Samos was defeated. According to Plutarch, it was thought that Aspasia, who came from Miletus, was responsible for the Samian War, and that Pericles had decided against and attacked Samos to gratify her.