Neighbors
In this poem, Byron uses "neighbors" to refer to those in neighboring countries who may be undergoing oppression or any sort of inconvenience that imposes on their liberties. He ironically advises enterprises adventurers to go to war on behalf of these neighbors, who come to symbolize any people other than oneself who might be in want of assistance. This language symbolization mirrors that of Mark 12:31, where Jesus commands his disciples to "Love your neighbor as yourself."
Greece and Rome
The ancient civilizations of Greece and Rome are legendary symbols of the ideals of mankind. Greece was a place of incredible culture and philosophy, representing the highest form of the contemplative man. Rome, on the other hand, represents the ideal man of discipline and action, taking steps to ensure his own success. These cultures provide Byron with precedents to reference in his ironic exhortation to greatness.
Irony
Irony is a motif in this poem; Byron's tone is slightly earnest but largely sarcastic, as evidenced by lines such as "Let him think of the glories of Greece and of Rome, / And get knock'd on the head for his labours", as well as "Then battle for freedom wherever you can / And, if not shot or hang'd, you'll get knighted." It can also be seen in the seemingly innocuous phrase "is always as nobly requited," meaning that even if you sacrifice yourself for the good of someone else, they probably won't do the same for you.
Shot/Hanged
Byron uses the image of someone being shot or hanged as an ironic deterrent from entering into needless war. He makes the statement in a light, almost quippy fashion, but the subject matter is far from it: prisoners of war, if not shot on the battlefield, are often hanged for their crimes. These punishments symbolize all the reasons for not going to war, rooted in self-preservation.
Knighted
On the other hand, Byron uses knighthood as an ironic incentive for going to war. If you aren't killed for your efforts, he says, you will receive a title that is, to be honest, mostly meaningless. He says that the risk is worth it while meaning the exact opposite. Knighthood therefore symbolizes the meager rewards for going to war in someone else's interest.
