Written four hundred years before the birth of Christ, this detailed contemporary account of the long life-and-death struggle between Athens and Sparta stands an excellent chance of fulfilling its author's ambitious claim. Thucydides himself (c.460-400 BC) was an Athenian and achieved the rank of general in the earlier stages of the war. He applied thereafter a passion for accuracy and a contempt for myth and romance in compiling this factual record of a disastrous conflict.
What Benedict Evans says
This is one of the best military history books of all time. Thucydides more or less invented impartial, accurate history as we know it, and gives a detailed account of the defining struggle of Classical Greece.