Prospero has long been regarded as an alter ego of Shakespeare, largely because of the famous speech in which Propsero proclaims,
Our revels now are ended. These our actors,
As I foretold you, were all spirits and
Are melted into air, into thin air:
And, like the baseless fabric of this vision,
The cloud-capp'd towers, the gorgeous palaces,
The solemn temples, the great globe itself,
Ye all which it inherit, shall dissolve
And, like this insubstantial pageant faded,
Leave not a rack behind.
The reference to the "great globe" has often been read as an allusion to the Globe Theatre, and The Tempest has often been read as a kind of valediction by Shakespeare to his theatrical career.
It should be noted, however, that some critics regard this view as an over-simplification, and it should also be noted that some critics regard Prospero as a highly unattractive figure.