The shipwreck of the enchanted island which Miranda witnesses and moves her heart to pity, provides the occasion to Prospero’s narration of his past history to Miranda. To explain the shipwreck which as Miranda understands, is caused by her father’s magic power, Prospero has to go back to his past history to show the connection of the shipwreck with it.
All that Miranda can remember of the past is that she had several women to attend upon her. Her memory does not carry her any farther. Prospero tells Miranda that he is the Duke of Milan and Miranda is a Princess. He also narrates that he had abdicated day-to-day administration of the Kingdom to Antonio, his brother. Prospero admits that the books held more attraction than his duties and unknowingly but willingly, he gave the opportunity to Antonio to grasp the reins of the Kingdom. Antonio used his power to undermine Prospero and plot a conspiracy against him. Prospero’s trust in his brother proved unwise when Antonio formed an alliance with the King of Naples to oust Prospero. Prospero and his three-year-old daughter were placed in a small, breaking-down boat and put on the sea. Gonzalo, a sympathetic courtier, provided them with rich garments, linens and other necessities. He also provided Prospero with books from his library. Eventually, Prospero and Miranda arrived on the uninhabited island and have been there since then.
As to the connection of this narrative with the shipwreck that now engages Miranda’s attention, Prospero points out to her that ‘Fortune’, which seems to be favouring him now, has placed his enemies in his power: that if he were to rise again, he must take advantage of this moment. He implies that the shipwreck which Miranda had witnessed lately is but a sequel to the narrative of his past misfortunes, which now relate to Miranda.