And now that he was in possession of Athens, he at once laid plans against Sparta. Near Mantineia, where Archidamus the king confronted him, he conquered and routed his foe, and then invaded Laconia.
Edition :
Plutarch. Plutarch's Lives. with an English Translation by. Bernadotte Perrin. Cambridge, MA. Harvard University Press. London. William Heinemann Ltd. 1920. 9.
Remark :
perpetrator: The New Pauly states that Archidamus was probably killed there.
http://referenceworks.brillonline.com/entries/brill-s-new-pauly/archidamus-e132330 date: The date is taken from the New Pauly. http://referenceworks.brillonline.com/entries/brill-s-new-pauly/archidamus-e132330 long-term consequence: Demetrius wins another victory over a second Spartan army. This is mentioned later in the paragraph.
