King Lear: The oldest daughter Goneril

Goneril really is the target of his fury.

Lear is absolutely horrible to Goneril, in a way that he doesn't speak to the other two.

King Lear: The middle daughter Regan

[Regan] uses sex to manipulate men, in a way that Goneril doesn't. She uses her femininity, and the power of sex even with her own father to get what she wants.

King Lear: The youngest daughter Cordelia

The stubbornness in him can also be the stubbornness in her.

King Lear (Act I, scene ii)

EDMUND

Thou, nature, art my goddess; to thy law
My services are bound. Wherefore should I
Stand in the plague of custom, and permit
The curiosity of nations to deprive me,
For that I am some twelve or fourteen moon-shines
Lag of a brother? Why bastard? wherefore base?
When my dimensions are as well compact,
My mind as generous, and my shape as true,
As honest madam's issue? Why brand they us
With base? with baseness? bastardy? base, base?
Who, in the lusty stealth of nature, take
More composition and fierce quality
Than doth, within a dull, stale, tired bed,
Go to the creating a whole tribe of fops,
Got 'tween asleep and wake? Well, then,
Legitimate Edgar, I must have your land:
Our father's love is to the bastard Edmund
As to the legitimate: fine word,--legitimate!
Well, my legitimate, if this letter speed,
And my invention thrive, Edmund the base
Shall top the legitimate. I grow; I prosper:
Now, gods, stand up for bastards!

King Lear (Act I, scene ii), by William Shakespeare

King Lear: Settings and locations

It's a pretty speedy spiral through the social strata.

King Lear: A dictator's regime

It's also deliberate that the supernumerary are all 6-foot, that there's a real sense of scale and power.  I want them to be physically threatening. 

King Lear: Goneril and Regan

If you imagine that [Goneril and Regan] start in very different positions on the graph, and they meet when they're finally kicking [King Lear] out.