Look what I speak, my life shall prove it true

Look what I speak, my life shall prove it true:
That Mowbray hath received eight thousand nobles
In name of lendings for your Highness’ soldiers,
The which he hath detained for lewd employments,
Like a false traitor and injurious villain.

And, by the glorious worth of my descent,
This arm shall do it, or this life be spent.

Besides I say, and will in battle prove,
Or here or elsewhere to the furthest verge
That ever was surveyed by English eye,
That all the treasons for these eighteen years
Complotted and contrivèd in this land
Fetch from false Mowbray their first head and spring.
Further I say, and further will maintain
Upon his bad life to make all this good,
That he did plot the Duke of Gloucester’s death,
Suggest his soon-believing adversaries,
And consequently, like a traitor coward,
Sluiced out his innocent soul through streams of blood,
Which blood, like sacrificing Abel’s, cries
Even from the tongueless caverns of the earth
To me for justice and rough chastisement.
And, by the glorious worth of my descent,
This arm shall do it, or this life be spent.