Dionysios A. Zakythinos or Zakythenos (Greek: Διονύσιος Α. Ζακυθηνός; 1905 in Lixouri, Kefalonia – 18 January 1993, in Athens) was a leading Greek Byzantinist. Zakythinos was born in Kefalonia in 1905. After graduating from the University of Athens in 1927, he went to the Sorbonne, which at the time was a major center of Byzantine studies with scholars like Charles Diehl and Ferdinand Lot. His first major work was a detailed study of the late Byzantine Despotate of the Morea, published in French (Le despotat grec de Morée (1262–1460)) in two volumes, one in 1932 and the other, delayed by World War II, in 1953. From 1939 to 1970 he taught Byzantine and Modern Greek History in the University of Athens (among his students there were Angeliki Laiou, Nikolaos Oikonomides and ), while in 1937–19