The Concept of History, Chapter 2 of "Between Past and Future" by Hannah Arendt

When we say history is written by the victors, we are assuming or accusing the historians of writing propaganda.  But as Hannah Arendt makes clear in the 2nd chapter of Between Past and Future history began with Homer's impartial view--writing about greatness and courage on both sides of the tragic war that lead to the founding of Rome by the defeated.  

Here is Arendt on impartiality in history in Ancient Greece:

Impartiality, and with it all true historiography, came into the world when Homer decided to sing the deeds of the Trojans no less than those of the Achaeans, and so to praise the glory of Hector no less than the greatness of Achilles. This Homeric impartiality as it is echoed by Herodotus who set out to prevent “the great and wonderful actions of the Greeks and the Barbarians from losing their due meed of glory,” is still the highest type of objectivity we know. Not only does it leave behind the common interest in one's own side and one's own people, which up to our own days characterizes almost all national historiography, but it also discards the alternative of victory or defeat which moderns have felt expresses the “objective” judgment of history itself and does not permit it to interfere with what is judged to be worthy of immortalizing praise. Somewhat later, and most magnificently expressed in Thucydides, there appears in Greek historiography still another powerful element that contributes to historical objectivity. It could come to the foreground only after long experience in polis-life, which to an incredibly large extent consisted of citizens talking with one another. In this incessant talk, the Greeks discovered that the world we have in common is usually regarded from an infinite number of different standpoints, to which correspond to the most diverse points of view. In a sheer inexhaustible flow of arguments, as the sophists presented them to the citizenry of Athens, the Greek learned to exchange his own viewpoint, his own “opinion”—in the way the world appeared and opened up to him δοκει μοι, “it appears to me,” from which comes δοξα, or “opinion”—with those of his fellow citizens. Greeks learn to understand—not to understand one another as individual persons, but to look upon the same world from one another's standpoint, to see the same in very different and frequently opposing aspects. The speeches in which Thucydides makes articulate the standpoints and interests of the warring parties, are still a living testimony to the extraordinary degree of this object activity.

The Concept of History, Chapter 2 of Between Past and Future by Hannah Arendt, pg. 51-2

I wrote about the Preface of Between Past and Future here.