The Peloponnesian War between Sparta and Athens began in 431 BC. and it would extend for almost 28 years. In the end, Sparta prevailed, but its hegemony would not last long, since first Thebes and then Macedonia would end up imposing themselves on the Greek world. Here we have already seen several episodes of that conflict.
At the end of the first year of the war, the Athenians, as was their custom, gathered for a ceremony to honor and remember the fallen. As Thucydides tells, it consisted of a procession that accompanied the ten coffins (cypress chests, one for each Athenian tribe, plus one always empty in memory of the disappeared) to their burial place in the Ceramic, the most important cemetery in Athens. , which can still be visited today. There, a speaker chosen from among the leading men of the polis, gave a laudatory speech.
On that occasion, the person in charge of the prayer was Pericles, ruler and first citizen of Athens, who begins modestly and eulogizes, not only the fallen, but also Athens itself, at a key moment in its history.
That speech by Pericles is, in the opinion of Thomas Cahill and many other scholars, the most famous speech in history. It is possible that the reader who does not know the speech thinks that he has never heard it. But he's wrong, as many parts of it will be familiar to you if you've been following Western politics for the last two or three centuries, at least. 
And it is that many later speeches of politicians of the culture that emanates from Ancient Greece, were inspired or directly copied parts of the funeral oration of Pericles.
The speech begins with a praise of the tradition of public burial of the fallen, and with a warning that the speaker's words will not satisfy everyone.
According to Thomas Cahill and other experts, this modest beginning inevitably reminds us of Lincoln's words at Gettysburg:
In that same ceremony, the longest prayer was given by Edward Everett, who began by describing the Athenian example .
Pericles praises the achievements of the fallen, but glosses over the military victories of the past and focuses instead on highlighting how Athens got to the present moment, and the form of government they were so proud of, democracy.
He continues to highlight the equality of all citizens before justice (free citizens, of course) and the extension of these principles to foreign policy as well as the opening of the city to foreigners.
He then goes on to point out how magnanimous the Athenians are with others, generous in their help, and confident in the validity of their institutions.
In these words we can trace Kennedy's inaugural address:
And at the climax of the speech Pericles links the greatness of the city with the deceased heroes, and expresses the inevitable conclusion that happiness is based on freedom, and freedom on courage.
Pericles' emphasis on sacrifice for freedom is echoed in the famous words, blood, sacrifice, sweat and tears, Winston Churchill to the British during World War II in his first speech as Prime Minister. It is no coincidence that Churchill knew very well the work of Thucydides and the Athenian prayer.
Finally Pericles ends with a short epilogue, reminding the audience of the difficulty of talking about the dead.
Thucydides warns early in his work that the speeches he transcribes are not verbatim records, but represent the ideas of what was said. It is certain that Pericles gave that speech and that, in essence, he said what Thucydides wrote, but it is reasonable to think that the historian expressed it in his own words.
On the other hand, the authorship of the funeral oration is unclear. Plato, for example, in his Menexeno , is attributed to Aspasia, the companion of Pericles. But we must not forget that Plato did not like democracy at all, and much less Pericles.
Some thinkers, such as Umberto Eco, expressed their rejection of what they consider a political use by Pericles of the fallen, as propaganda not for democracy, but for populism.
In any case, Pericles' funeral oration perfectly characterizes the moment and the spirit of that Athens, which he identifies as the land of freedom and the home of the brave (like the American home of the brave ) that, after his death the following year, would never recover its splendor.