[G1911]

In the play, through trickery and depravity while posing as a devout and modest man, Richard makes himself King illegitimately. As part of the saga he has his nephew, the rightful king, murdered in the tower where a King was traditionally to stay before his coronation. Richard's reign is short, and he dies ingloriously, deserted by many of his followers on the field, begging for a horse.
I am determined to prove a villain,
And hate the idle pleasures of these days.
Plots I have laid, inductions dangerous,
By drunken prophecies, libels and dreams

I presume the literary illusion was to the dubious ethics and doubtful legitimacy of the self-proclaimed king's.