It is hard to ignore the parallels between Prospero arriving at this island and taking it over, seizing power from Caliban and the discovery of the New World and the attitudes displayed by the European explorers to the inhabitants of these so-called "undiscovered" lands. Given the context at the time of writing this play, when such new worlds became the intense focus of much speculation, many critics have arrived at colonial or post-colonial readings of this play. From Caliban's perspective, however, the arrival of Prospero and Miranda has been a profoundly negative thing. He says in Act I scene 2 that the island was his, left to him by his mother, Sycorax, until Prospero arrived and now he finds himself locked away:
For I am all the subjects that you have,
Which first was mine own king, and here you sty me
In this hard rock, while you do keep from me
The rest o'th'island.
Caliban is therefore oppressed because he was his own "king" until Prospero came and seized that kingship from him, effectively imprisoning Caliban and turning him into a slave and making him work for Prospero, stripping him of what power, dignity and freedom he once had. Miranda of course rails against him at this point, protecting her father and citing the love that both she and her father lavished upon Caliban. However, it is clear that learning their tongue has only allowed Caliban to become more aware of his difference and his inferiority, highlighting even further his oppressed status.