Browning wrote this poem in 1842 for Macready's son, who was ill. He had also written the Pied Piper of Hamelin at the same time.
Crescenzio, the Pope's Legate at the High Council, Trent,
Year Fifteen hundred twenty-two, March Twenty-five, intent
On writing letters to the Pope till late into the night,
Rose, weary, to refresh himself, and saw a monstrous sight:
(I give mine Author's very words: he penned, I reindite.)
A black Dog of vast bigness, eyes flaming, ears that hung
Down to the very ground almost, into the chamber sprung
And made directly for him, and laid himself right under
The table where Crescenzio wrote, who called in fear and wonder
His servants in the ante-room, commanded every one
To look for and find out the beast: but, looking, they found none.
The Cardinal fell melancholy, then sick, soon after died:
And at Verona, as be lay on his death-bed, he cried
Aloud to drive away the Dog that leapt on his bedside.
Heaven keep us Protestants from harm: the rest . . . no ill betide!