Two other notable acts of brutality were the massacres of Italian troops at the islands of Cephallonia and Kos in September 1943 , during the German takeover of the Italian occupation areas . In Cephallonia , the 12,000-strong Italian '' Acqui '' Division was attacked on 13 September by elements of 1 . '' Gebirgs-Division '' with support from Stukas , and forced to surrender on 21 September after suffering some 1,300 casualties . The next day , the Germans began executing their prisoners and did not stop until more than 4,500 Italians had been shot . The 4,000 or so survivors were put aboard ships for the mainland , but some of them sank after hitting mines in the Ionian Sea , where another 3,000 were lost . The Cephallonia massacre serves as the background for the novel '' Captain Corelli 's Mandolin ''
began executing their prisoners
Massacre of the Acqui Division
Axis occupation of Greece