Character Analysis
Another one of many depictions of tyranny in Book 5, Adicia and the Souldan represent the inherent injustice and bestiality that Western Europeans associated with Muslims—"Souldan" is another word for "Sultan." However, there's also a twist: the tyrannous reign of the Souldan is also compared to the Spanish King Phillip II, a major threat to the English throne during Spenser's lifetime.
Phillip II was a devout Catholic, whereas Elizabeth was a devout Protestant, so by aligning Phillip with representations of Islamic rulers, Spenser is subtlety connecting the error of Catholicism and its leadership style to the errors of Islam. Adicia, whose name literally means "injustice," acts therefore as his advisor, suggesting that Phillip's error-filled rule is guided by, and even marred to, the embodiment of injustice itself.