Comment on Manfred’s greed for power in the novel.
Manfred, Prince of Otranto, is driven throughout Walpole's novel by an overwhelming greed for power, or more exactly a desperate greed to retain the power his family has wrongfully seized. This ambition shapes almost every action he takes and finally destroys everything he tries to protect.
Root of the greed: an usurped throne. Manfred is the grandson of a usurper. His whole life is haunted by an ancient prophecy that the castle and lordship of Otranto shall pass from his family "whenever the real owner should be grown too large to inhabit it." His greed for power is therefore also fear: he clings to a title he knows is not lawfully his.
Obsession with a male heir. When his sickly son Conrad is crushed to death by a gigantic helmet on his wedding morning, Manfred's first concern is not grief but the survival of his dynasty. To secure the succession he resolves to divorce his loyal wife Hippolita, whom he now calls barren, and to marry Isabella, his dead son's betrothed. He is willing to commit adultery in effect, to shame a faithful wife, and to force a horrified young woman, all to keep power in his hands.
Tyranny and cruelty. His ambition makes him ruthless. He pursues the fleeing Isabella through the castle vaults, imprisons the innocent Theodore and orders his execution on suspicion, and browbeats the servants and even the friar who stand in his way. He treats persons as mere obstacles to or instruments of his political survival.
Self-destruction. Manfred's greed is ultimately self-defeating. In the darkness he stabs to death his own daughter Matilda, mistaking her for Isabella, thus killing the child he might have loved in his blind rush to secure the succession. The prophecy is fulfilled: the true heir Theodore is revealed, and the shattered Manfred confesses his family's guilt and retires with Hippolita into a convent.
Walpole uses Manfred to show that greed for power, especially power founded on injustice, breeds tyranny and finally consumes the tyrant himself. His downfall carries the novel's clear moral warning against overreaching ambition.