The ancient Greeks believed that Troy was located near the Dardanelles and that the Trojan War was a historical event of the 13th or 12th century BC, but by the mid-19th century AD, both the war and the city were widely seen as non-historical. In 1868, however, the German archaeologist Heinrich Schliemann met Frank Calvert, who convinced Schliemann that Troy was a real city at what is now Hisarlik in Turkey. On the basis of excavations conducted by Schliemann and others, this claim is now accepted by most scholars.

Source : Wikipedia

In other words, the question of whether the Trojan Wars were an invention of Greek mythology, or whether they actually happened, is still open.

Note that one of the most famous accounts of the wars is in Homer's Iliad. - but Homerplugin-autotooltip__plain plugin-autotooltip_bigHomer

"Homer (Ancient Greek: Ὅμηρος [hómɛːros], Hómēros) is best known as the author of the Iliad and the Odyssey. He was believed by the ancient Greeks to have been the first and greatest of the epic poets. Author of the first known literature of Europe, he is central to the Western canon. also has an unknown background.