Christina Rossetti: My Dream

Hear now a curious dream I dreamed last night
Each word whereof is weighed and sifted truth.

I stood beside Euphrates while it swelled
Like overflowing Jordan in its youth:
It waxed and coloured sensibly to sight;
Till out of myriad pregnant waves there welled
Young crocodiles, a gaunt blunt-featured crew,
Fresh-hatched perhaps and daubed with birthday dew.
The rest if I should tell, I fear my friend
My closest friend would deem the facts untrue;
And therefore it were wisely left untold;
Yet if you will, why, hear it to the end.

Each crocodile was girt with massive gold
And polished stones that with their wearers grew:
But one there was who waxed beyond the rest,
Wore kinglier girdle and a kingly crown,
Whilst crowns and orbs and sceptres starred his breast.
All gleamed compact and green with scale on scale,
But special burnishment adorned his mail
And special terror weighed upon his frown;
His punier brethren quaked before his tail,
Broad as a rafter, potent as a flail.
So he grew lord and master of his kin:
But who shall tell the tale of all their woes?
An execrable appetite arose,
He battened on them, crunched, and sucked them in.
He knew no law, he feared no binding law,
But ground them with inexorable jaw:
The luscious fat distilled upon his chin,
Exuded from his nostrils and his eyes,
While still like hungry death he fed his maw;
Till every minor crocodile being dead
And buried too, himself gorged to the full,
He slept with breath oppressed and unstrung claw.
Oh marvel passing strange which next I saw:
In sleep he dwindled to the common size,
And all the empire faded from his coat.
Then from far off a wingèd vessel came,
Swift as a swallow, subtle as a flame:
I know not what it bore of freight or host,
But white it was as an avenging ghost.
It levelled strong Euphrates in its course;
Supreme yet weightless as an idle mote
It seemed to tame the waters without force
Till not a murmur swelled or billow beat:
Lo, as the purple shadow swept the sands,
The prudent crocodile rose on his feet
And shed appropriate tears and wrung his hands.

What can it mean? you ask. I answer not
For meaning, but myself must echo, What?
And tell it as I saw it on the spot.