You will know of course, that Richard did not live long enough to enforce his wish.
Edmund was made Duke of York in 1385, and was the first to hold that title. He was the father of Richard of Conisburgh, grandfather of Richard, Duke of York and the great grandfather of Richard III, Edward IV, and George Duke of Clarence.
You could argue that Edmund's character is not unlike that of his grandson, Richard Duke of York. Both were loyal to the throne and both were charged with protectorship of England in the king's absence. Both men advised well (if the speech below is anything to go by) but were ignored.
In gross rebellion and detested treason:
Thou art a banish'd man, and here art come
Before the expiration of thy time,
In braving arms against thy sovereign.
Well, well, I see the issue of these arms:
I cannot mend it, I must needs confess,
Because my power is weak and all ill left:
But if I could, by Him that gave me life,
I would attach you all and make you stoop
Unto the sovereign mercy of the king;
But since I cannot, be it known to you
I do remain as neuter. So, fare you well"
Of his last years it has been said - "Jaye styll in his castell, and medled with nothynge of the busynesse of Englande"
Edmund died at King's Langley on the 1st of August 1402.