Called the Father of History. ?485-?425 B.C., Greek historian, famous for his History dealing with the causes and events of the wars between the Greeks and the Persians (490-479)

From the souvenir book of the 15th IVU World Vegetarian Congress, India, 1957 (uncorroborated):

- the Father of History; a very abstemious vegetarian, often partaking of but one meal per day and that of parched wheat and fruit. He abhorred the killing of the innocent grazing herds, still more the bloody sacrifices seen about the Temples, and still more the eating of the flesh sacrificed to the Gods.

"Why cause suffering, to these inferior and innocent orders of being and why take the life that only the gods could give ; and why cut flesh, yet dripping with innocent blood? Do not the oracles condemn it? Do they not advise lentils, and grains and fruits that ripen in the sun?

From Wikipedia on History of Vegetarianism:

The earliest European references to a vegetarian diet occur in Homer (Odyssey 9, 82–104) and Herodotus, who mention the Lotophagi (Lotus-eaters), an indigene people on the North African coast, who according to Herodotus lived on nothing but the fruits of a plant called lotus. Diodorus Siculus transmits tales of vegetarian peoples or tribes in Ethiopia, and further stories of this kind are narrated and discussed in ancient sources. All of them, however, display legendary traits or appear in a mythical context; hence they cannot be regarded as evidence for the historical existence of such peoples.

• Herodotus (link to Google Books) - trans. Rev. William Beloe 1831. P.236: The neck of land which stretches from the country of the Gindanes towards the sea is possessed by the Lotophagi who live entirely upon the fruit of the lotos