He was victorious in the Panathenaic Games that was held before the Battle of Marathon.
The Nike ( some say it is Iris) of the Kallimachos Memorial on the Acropolis. Historians say that Kallimachos offered this statue before the battle of Marathon but he was not so lucky. He died and his friends finally modified the inscription including the lines: "who, being polemarch for the Athenian front, won honor from Marathon, and who furious Ares destroyed; and he left behind this memory of his honor to the children of the Athenians." Fragments of the sculpture were found from which the above reconstruction was made. Kallimachos was a hero as his voice was important in the final decision of the Greeks to attack the Persian army in Marathon. Miltiades according to Herodotus convinced Kallimachos with these words:
“With thee it rests, Kallimachos, either to bring Athens to slavery, or, by securing her freedom, to leave behind thee to all future generations a memory beyond even Harmodius and Aristogeiton. For never since the time that the Athenians became a people were they in so great a danger as now. If they bow their necks beneath the yoke of the Medes, the woes which they will have to suffer when given into the power of Hippias are already determined on; if, on the other hand, they fight and overcome, Athens may rise to be the very first city in Greece. How it comes to pass that these things are likely to happen, and how the determining of them in some sort rests with thee, I will now proceed to make clear. We generals are ten in number, and our votes are divided; half of us wish to engage, half to avoid a combat. Now, if we do not fight, I look to see a great disturbance at Athens which will shake men’s resolutions, and then I fear they will submit themselves; but if few fight the battle before any unsoundness show itself among our citizens, let the gods but give us fair play, and we are well able to overcome the enemy. On thee therefore we depend in this matter, which lies wholly in thine own power. Thou hast only to add thy vote to my side and thy country will be free, and not fee only, but the first state in Greece. Or, if thou preferest to give they vote to them who would decline the combat, then the reverse will follow.” Herodotus History Book VI
Kallimachos was killed in the battle
.. As you go to the portico which they call painted, because of its pictures, there is a bronze statue of Hermes of the Market-place, and near it a gate.... At the end of the painting are those who fought at Marathon; the Boeotians of Plataea and the Attic contingent are coming to blows with the foreigners. In this place neither side has the better, but the center of the fighting shows the foreigners in flight and pushing one another into the morass, while at the end of the painting are the Phoenician ships, and the Greeks killing the foreigners who are scrambling into them. Here is also a portrait of the hero Marathon, after whom the plain is named, of Theseus represented as coming up from the under-world, of Athena and of Heracles. The Marathonians, according to their own account, were the first to regard Heracles as a god. Of the fighters the most conspicuous figures in the painting are Callimachus, who had been elected commander-in-chief by the Athenians, Miltiades, one of the generals, and a hero called Echetlus, of whom I shall make mention later. Pausanias
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