Analysis of The First Black Flag

JOB. Hast thou ne'er heard men say
That, in the Black Wood, 'twixt Cologne and Spire,
Upon a rock flanked by the towering mountains,
A castle stands, renowned among all castles?
And in this fort, on piles of lava built,
A burgrave dwells, among all burgraves famed?
Hast heard of this wild man who laughs at laws--
Charged with a thousand crimes--for warlike deeds
Renowned--and placed under the Empire's ban
By the Diet of Frankfort; by the Council
Of Pisa banished from the Holy Church;
Reprobate, isolated, cursed--yet still
Unconquered 'mid his mountains and in will;
The bitter foe of the Count Palatine
And Treves' proud archbishop; who has spurned
For sixty years the ladder which the Empire
Upreared to scale his walls? Hast heard that he
Shelters the brave--the flaunting rich man strips--
Of master makes a slave? That here, above
All dukes, aye, kings, eke emperors--in the eyes
Of Germany to their fierce strife a prey,
He rears upon his tower, in stern defiance,
A signal of appeal to the crushed people,
A banner vast, of Sorrow's sable hue,
Snapped by the tempest in its whirlwind wrath,
So that kings quiver as the jades at whips?
Hast heard, he touches now his hundredth year--
And that, defying fate, in face of heaven,
On his invincible peak, no force of war
Uprooting other holds--nor powerful Caesar--
Nor Rome--nor age, that bows the pride of man--
Nor aught on earth--hath vanquished, or subdued,
Or bent this ancient Titan of the Rhine,
The excommunicated Job?