About the Faerie Queene...

This letter was wrote with a special intention behind. That's why it is an allegory, because "between the lines" you can find a "secret meaning".
Spencer with his book was telling his deep thoughts about the society in those times. So, with his letter to Sir Walter he wanted to clarify that he wasn't a revolutionary thinker, because it was good for Spencer to stand aloof of social conflicts or he could die. However Spencer entwined though his different characters the ideal that he wanted to outside his book. For example he talks about values putting it names (his character's names)in orer to disguising his real intetions as I said before.
On the whole Spencer was really smart doing this letter explaining why he wanted to write his book. He also xplain in a clear way the plot of the story in order to dissipate future judgements against him