Short answers, pulled from the story.
The oldest written evidence of Greek is the Linear B script, developed by Mycenaean Greeks around 1600 BC by adapting the Minoan Linear A syllabic writing system. The oldest inscriptions in Linear B date to around 1450 BC.
The modern Greek state was formally established in 1829, after Greeks liberated part of their historic homelands, including the Peloponnese, from the Ottoman Empire. The first Greek constitution dates to 1822.
The Treaty of Lausanne between Greece and Turkey in 1923 agreed to use religion as the determinant for ethnic identity in a population exchange. Approximately 1.5 million Greeks were displaced in the process, with over a million having already been driven out before the treaty was signed. Around 450,000 Muslims were resettled in Turkey.
Under the Ottoman millet system, religion defined national groups, so the label "Greeks" was applied to all Orthodox Christians regardless of language or ethnicity. The Phanariotes, an educated merchant and professional class in Constantinople, preserved Greek learning and commerce, and the three leading centers of Greek education on the eve of the 1821 War of Independence were Chios, Smyrna, and Aivali, all major commercial hubs.
The total size of the Greek diaspora outside Greece and Cyprus is contested. Official census figures indicate around three million Greeks living abroad, while the World Council of Hellenes Abroad estimates roughly seven million worldwide. Major diaspora centers include New York City, Chicago, Sydney, Melbourne, London, Toronto, and Sao Paulo.
Byzantine grammarians carried ancient Greek grammatical and literary studies to Western Europe in person and in writing during the 15th century, providing major impetus to the Italian Renaissance. The Aristotelian philosophical tradition ran nearly unbroken in the Greek world for close to two thousand years, until the Fall of Constantinople in 1453. The monks Cyril and Methodius, from Thessalonica, also created the first Slavic alphabet, extending Greek learning into Slavic civilization.