The king sends (Derwentwater) a summons to London. His wife bids him make his will before going. As he goes along his way, ill portents greet him. Arriving in London, he is condemned to death. (He gives gifts to the poor and is executed)
Although based on a historical incident, this ballad is a rather curious amalgam of material from other pieces; the opening is straight from "Sir Patrick Spens" [Child #58],
while the incident of the nosebleed portending doom is found in "The Mother's Malison, or Clyde's Water" [Child 216]. The making of the will is harder to trace, but the idea is commonplace.
There is an obvious urge to confuse this with "Derwentwater's Farewell," by Robert Surtees, but Child explicitly and correctly denies this link.
Derwentwater seems by all accounts to have been popular, and other poems were written of his death. In this case, it would appear that an unknown poet (Surtees?) took pieces of older ballads to produce a song for the occasion.
The night of Derwentwater's execution witnessed a particularly bright aurora, and the aurora is sometimes called "Derwentwater's Lights" as a result. But this usage, like the ballad itself, seems to have faded out with time. - RBW