"Ioannis Vlachos", known as Daskalogiannis was a Cretan rebel against Ottoman rule in the 18th century. Ioannis Vlachos was a wealthy Cretan ship-owner, born in Anopolis village, Sfakiá, Crete. Because he had some education, his compatriots called him 'Daskalos' (teacher), hence Daskalos plus Ioannis = Daskalogiannis. He is referred to as a town clerk and chairman of the country of Sfakiá as early as 1750. Wikipedia
The definitive Wikipedia entry for Daskalogiannis. Wikipedia is the biggest multilingual free-content encyclopedia on the Internet. en.wikipedia.org/wiki/Daskalogiannis