Prospero from The Tempest is the rightful Duke of Milan and father to Miranda who he loves. In the plot, he was usurped by his brother and sent on a boat to his death but survived by landing on the island.
Prospero possesses magical powers and is able to conjure spirits and nymphs to perform tasks. With Ariel's help, he conjures the tempest at the start of the play.
Prospero is quite a foreboding character dealing out punishments and treating his servants with contempt, raising questions about his morality and fairness. Both Ariel and Caliban want to be free of their master which suggests he is not easy to work for.
Ariel and Caliban represent the two sides of Prospero's personality – he can be kind and generous but there is also a darker side to him. Prospero is accused by Caliban of stealing his island and thus usurping power like his brother.
Prospero's power in The Tempest is knowledge and his beloved books demonstrate this – these inform his magic.
Having been wronged by many of the characters, he graciously forgives them. Prospero's desire to rule the island reflects his brother Antonio's desire to rule Milan – they go about realizing their desire in similar ways but Prospero absolves himself at the end of the play by setting Ariel free and forgiving his persecutors.