How do we know that Shelley's "Adonais" refers to Byron and Moore?

Question

In every site I've seen that analyzes Shelley's Adonais, they all agree that in the following stanza the "Pilgrim of Eternity" refers to Byron. Here is one example:

From stanza 30 to 35, Shelley says that contemporary poets, in the guise of mountain shepherds with “garlands sere” and “magic mantles rent”, come to pay their tribute. The poet chooses Byron and Moore as the first two mourners. It is to be noted here that Byron and Moore did not really feel the sentiments that Shelley attributes to them.

I don't quite see how this is entirely certain. Even more uncertain is why they believe Thomas Moore is referred to. I suppose you could say, well, we know who attended Keats' funeral, and Byron best fits the description. Looking at Keats' biography on Wikipedia it seems that Joseph Severn, Leigh Hunt and Charles Armitage Brown also attended his funeral, so how do we know they are not the ones in question?

Here are the stanzas in question:

30.
Thus ceased she: and the mountain shepherds came,
Their garlands sere, their magic mantles rent,
The Pilgrim of Eternity, whose fame
Over his living head like Heaven is bent,
An early but enduring monument,
Came, veiling all the lightnings of his song
In sorrow, from her wilds Ierne sent
The sweetest lyrist of her saddest wrong,
And Love taught Grief to fall like music from his tongue.

31.
Midst others of less note, came one frail Form,
A phantom among men, companionless
As the last cloud of an expiring storm
Whose thunder is its knell, he, as I guess,
Had gazed on Nature's naked loveliness,
Actaeon-like, and now he fled astray
With feeble steps o'er the world's wilderness,
And his own thoughts, along that rugged way,
Pursued, like raging hounds, their father and their prey.

Answer 1

In his answer, Peter Shor has set out the wording in the text of Adonais that suggests the identification of the mourners.

But we don’t have to rely only on the text: there is also the epitext, the “textual materials that derive from a published work, e.g. reviews, interviews, etc., that contextualize the work and shape its public reception” (OED). In the case of Adonais there is a tradition of interpretation that we can look at: in particular, as soon as the poem was published, reviewers were confident in identifying Byron and Moore:

In the course of the poem some living writers are introduced, among whom Lord Byron is designated as

The Pilgrim of Eternity, whose fame
Over his living head like Heaven is bent
An early but enduring monument!

The poet of Ireland† is called, with equal brevity: and felicity,

The sweetest lyrist of her saddest wrong

_{Anon (1822). ‘On Mr Shelley’s New Poem, Entitled Adonais’. In The Examiner, number 757, 7th July 1822, p. 420.}

_{† See below for evidence that “poet of Ireland” refers to Moore.}

This shows that Shelley’s hints in Adonais were sufficiently clear for his contemporary readers, even if these hints seem obscure at a distance of two centuries.

Shelley himself confirmed that Byron is mentioned in the text, though he did not say explicitly where:

Lord Byron—I suppose from modesty on account of his being mentioned in it—did not say a word of “Adonais”, though he was loud in his praise of “Prometheus Unbound”: and, what you will not agree with him in, censure of “The Cenci.”

_{Percy Bysshe Shelley (26th August 1821). Letter to Leigh Hunt. In Roger Ingpen, ed. (1914). Letters of Percy Bysshe Shelley, volume II, p. 910. London: G. Bell.}

Other writers took up “pilgrim of eternity” as a sobriquet for Byron, indicating that they too understood Shelley to be referring to him in Adonais:

Byron, had I met him, instead of sending Finlay, would have been at Salona now. His name was the means chiefly of raising the loan in England. Thousands of people were flocking here: some had arrived as far as Corfu, and hearing of his death, confessed they came out to devote their fortunes, not to the Greeks or interest in the cause, but to the noble poet; and the pilgrim of eternity having departed, they turned back.

_{Edward Trelawny (29th April 1824). Letter to Leicester Stanhope. In Leicester Stanhope (1824). Greece in 1823 and 1824: Being a Series of Letters and Other Documents on the Greek Revolution, p. 331. London: Sherwood, Jones and Co.}

In our days it [Corinth] has still been a scene of contest: “Corinth is taken, and the Greeks have gained a battle in the Archipelago,” says Lord Byron, in a letter to Mr. Kinnaird, written in Greece a few months only before the warrior poet had become the “Pilgrim of Eternity.”

_{William Brockedon (1833). Finden's Illustrations of the Life and Works of Lord Byron, volume I. London: John Murray.}

How can I be confident that by “poet of Ireland” the anonymous reviewer in The Examiner, quoted above, meant “Thomas Moore”? Well, this phrase was a common sobriquet for Moore, meaning that he put the national sentiments of Ireland into verse. There was even a minor critical controversy over whether he deserved this name.

This piece [‘The Tear’], which were we to call merely beautiful, it would reflect little credit on our poetical taste, is from the pen of Thomas Moore, the celebrated living poet of Ireland.

_{Peter Forbes (1816). The Pocket Encyclopedia of Scottish, English, and Irish Songs, volume II, p. 37. Glasgow: Andrew & James Duncan.}

Like you I admire the lively and graceful genius of this man; like you I appreciate the amiable temperament and dispositions which lend a charm to his verses, more touching than any thing which liveliness, grace, and genius alone could confer; but I cannot consent for a moment to class Mr Moore with the great poets of England—no more can I persuade myself that he is likely to go down to posterity as the national poet of Ireland. The claim which has lately been set up for him† is one of no trifling import, it would not only assign to him a share of the same magnificent honours which have of right descended to Byron, Wordsworth, and Campbell, but mingle with his laurels another wreath such as the grateful affection of your own country has already woven for Scott and Burns.

_{‘Baron von Lauerwinkel’‡ (1818). ‘Remarks on the Poetry of Thomas Moore’. In Blackwood’s Edinburgh Magazine, October 1818, p. 1.}

_{† That is, although the critic objects to the sobriquet, he admits that it is widely applied to Moore. ‡ A pseudonym of John Gibson Lockhart.}

He [Pierre-Jean de Béranger] has been compared to Moore, which is doing much injustice to the national poet of Ireland.

_{Anon (1823). ‘French Poets of the Present Day’. In Blackwood’s Edinburgh Magazine, May 1823, p. 514.}

Answer 2

This is partially explained in the Project Gutenberg edition of Adonais. I believe you've misidentified the sections of the poem that refer to Byron and Moore, respectively.

Byron is described in:

The Pilgrim of Eternity, whose fame
Over his living head like Heaven is bent,
An early but enduring monument,
Came, veiling all the lightnings of his song
In sorrow,

and Moore by

                 from her wilds Ierne sent
The sweetest lyrist of her saddest wrong,
And Love taught Grief to fall like music from his tongue.

How can we be sure of this identification? The poem says (by "midst others of less note") that these were the two most famous people (let's leave Shelley aside) who attended the funeral.

Byron is quite famous, and was then. Thomas Moore was a very popular poet then (although Leigh Hunt may be more famous today).

Describing Byron as a "Pilgrim" is a big hint, since he had traveled extensively, and one of his long poems (whose main character shares some traits with Byron) was titled Childe Harold's Pilgrimage.

The word that gives away that the next lines refer to Thomas Moore is "Ierne". Ierne is either Ériu, the goddess of Ireland, or a metonym for Ireland itself. Moore is not only Irish, but his poetry is very much identified with Ireland—his most famous book of poetry is Irish Melodies, the first part of which was published in 1808, over a decade before Keats' funeral.

Stanzas 31–34 are identified by the Project Gutenberg edition of Adonais as describing Shelley himself, and Stanza 35:

What softer voice is hushed over the dead?
Athwart what brow is that dark mantle thrown?
What form leans sadly o'er the white death-bed,
In mockery of monumental stone,
The heavy heart heaving without a moan?
If it be he who, gentlest of the wise,
Taught, soothed, loved, honoured, the departed one.
Let me not vex with inharmonious sighs
The silence of that heart's accepted sacrifice.

as identifying Leigh Hunt. The reasons they give for believing Stanza 35 refers to Hunt are rooted in the relationships between Hunt, Keats, and Shelley, and do not seem to be tied to any specific words of the poem.

I also believe you're mistaken about who actually attended Keats' funeral in real life. Byron didn't. In a Project Gutenberg collection of Byron's letters, he writes to Shelley on April 26, 1821:

I am very sorry to hear what you say of Keats—is it actually true? I did not think criticism had been so killing. Though I differ from you essentially in your estimate of his performances, I so much abhor all unnecessary pain, that I would rather he had been seated on the highest peak of Parnassus than have perished in such a manner.

...

Had I known that Keats was dead—or that he was alive and so sensitive—I should have omitted some remarks upon his poetry, to which I was provoked by his attack upon Pope, and my disapprobation of his own style of writing.

I don't know which of the other people you list were there, either. Using poetic license, of course, Shelley is able to bring whomever he wants to Keats' funeral.

To explain some of the puzzling sentences in Byron's letter, Shelley had written to Byron that Keats died of an attack of rage after reading a bad review of his poetry; this belief of Shelley's is also given in the poem Adonais. Keats' death was actually caused by tuberculosis.

Answer 3

I cannot see how the 'sweetest lyrist' of Stanza 30 is not Moore. He was often paired together with Byron in poems and skits of the period (e.g. Shufflebotham's Dream in Blackwood's) because of their close friendship and the perception that they were the two greatest living 'Whig' poets.