What is the political significance of Trojan mythology in the Middle Ages?

Literary works of the Middle Ages on Troy, the twelfth and thirteenth century knight stories, have statements by two witnesses about the "Old Soldiers of Troy", regarding the destruction of Troy and these two witnesses are Diktys of Crete (first/third centuries C. E.) and Dares of Phrygia (second/fifth centuries C. E.). According to them, Franks, Bourgonians, Normandians, British, and Turks came from Trojan ancestry, just like the Romans. The legend about Franks' Roman ancestry was misinformed but proved quite useful for the political interests of the Franks, who were the subjects of a new empire since Charlemagne's reign. When the fourth Crusade that took place in 1202-1204 was directed to Constantinople instead of Jerusalem, the knights argued that they came to take revenge of the Trojan defeat in order to cover up their misdirected attacks. The Crusader Peter von Bracheux makes the following statement in replying to a general: "Troy belonged to our ancestors and the survivors of that land settled down in our homeland; because they were our ancestors, we came here to conquer their land once again." Crusaders and aristocrats in the Middle Ages became a part of this story through their claims of Troyan ancestry. The events that took place in Troy and its after effects show us that important origins of the Western culture and history lie in these lands. What is remarkable about the Middle Ages is that people saw themselves as a part of world history, thanks to Troy.