The first verse:
Onwards, onwards rode the six hundredDown the valley on their horses they thunderedAh, but was is them who really blunderedUh huh, it was the Manfreds
This refers to Alfred, Lord Tennyson's poem "The Charge of the Light Brigade." The Manfreds even borrow some specific words: "Half a league onward, / All in the valley of Death / Rode the six hundred" (lines 2-4) and "Some one has blunder'd" (line 12). "Thundered" also appears in Tennyson's poem, but it doesn't describe the brigade: "Cannon in front of them / Volley'd and thunder'd" (lines 20-21).
I'm not very confident in one line (the third) of my transcription of the second verse, but it's something like:
The Trojans waited at the gate for weeksIn a wooden horse into the city they sneakedPulled out and then, who was it? The Greeks?Uh huh, it was the Manfreds
In Book II of Virgil's Aeneid, Aeneas explains that the Greeks built a wooden horse, hid their soldiers inside, and left it by the city, ostensibly as an offering. The Trojans brought the horse into the city, and when night fell, the Greeks emerged and opened the gates for their fellow soldiers. In Book IV of The Odyssey, Menelaus briefly recounts this story too.