‘The sovereign beauty which I do admire, / Witness the world how worthy to be praised’: so begins the third sonnet in Edmund Spenser’s 1595 sonnet sequence Amoretti, written to celebrate his own marriage to his second wife, Elizabeth Boyle. As love poems to one’s newlywed bride go, it must have made the young Elizabeth blush with pride; the sonnet flatters her beauty using the courtly language of the sonnet sequence.
The sovereign beauty which I do admire,
Witness the world how worthy to be praised:
The light whereof hath kindled heavenly fire
In my frail spirit, by her from baseness raised;
That being now with her huge brightness dazed,
Base thing I can no more endure to view;
But looking still on her, I stand amazed
At wondrous sight of so celestial hue.
So when my tongue would speak her praises due,
It stopped is with thought’s astonishment:
And when my pen would write her titles true,
It ravish’d is with fancy’s wonderment:
Yet in my heart I then both speak and write
The wonder that my wit cannot endite.
In writing his Amoretti, Edmund Spenser (c. 1552-99) was greatly influenced by his friend Sir Philip Sidney, the quintessential Renaissance man, whose Astrophil and Stella (composed in the early 1580s but only published in 1591, five years after Sidney’s death) 
proved so popular that it spawned a raft of imitators and followers. ‘The Sovereign Beauty Which I Do Admire’, the third sonnet in Amoretti, shows how deep Sidney’s influence went, and the motif of the poem – the idea of struggling to write about a woman, only to have a Eureka moment which enables the poet to be able to write – is typical Sidney. (Compare his opening sonnet from Astrophil and Stella.)
We might summarise Spenser’s sonnet as follows: the woman the poet is attempting to write about is, if such a thing is possible, too beauty. Her beauty is so ‘sovereign’ or superior that it has raised the poor poet from his low status or ‘baseness’ (though ‘baseness’ also suggests moral turpitude, implying that her beauty is morally beneficent, and has led him down the path to goodness). But unfortunately, her beauty is so bright that it blinds and dazes him; he can no longer look on lesser things (‘Base’ makes a second appearance in the poem here), because they are so inferior to her.
But when he goes to tell the world of how beautiful she is, he is too stunned and astonished, and cannot find the words. And yet when he looks in his heart, the seat of his emotions, he can speak and write freely then, and so he can put the words down if he lets his heart, rather than his ‘wit’ or cleverness, lead the way. ‘Look in thy heart, and write’, as Sidney’s Muse said to him in that opening sonnet (linked above).
As Elizabethan sonnets go, ‘The Sovereign Beauty Which I Do Admire’ is fair enough, and well-executed. But its argument has nothing of the clever twists and turns, the proto-metaphysical wranglings we find in Sir Philip Sidney’s earlier sonnets in his Astrophil and Stella. This isn’t all Spenser’s fault: the poet who gave the world The Faerie Queene was no second-rate artist. But the sonnet’s straightforwardness (verging on the facile – we might paraphrase it even more succinctly as ‘I am too stunned by my beloved’s beauty to write about her – until I let my heart dictate, and then the words come easily’) is perhaps a problem engendered partly by its occasion as a sonnet celebrating a (happy) marriage, rather than Sidney’s poems, which enact the emotional drama of loving a woman who is married to someone else. Unrequited love is much easier to tear great poetry from; as Montherlant wrote, happiness writes white.
One thing we might observe, as a footnote to this analysis, is the rhyme scheme Spenser uses in this poem: abab bcbc cdcd ee. This is known, to this day, as the Spenserian sonnet, or Spenserian sonnet form, after Spenser invented it for Amoretti. It’s closer to the English or Shakespearean sonnet form (which, whilst named after Shakespeare, was actually invented by the Earl of Surrey), in that it comprises three quatrains and a concluding (rhyming) couplet. The ‘turn’ – what the Italians call the volta – comes at the beginning of the closing couplet, rather than earlier on, as it does in a Petrarchan sonnet. But Spenser’s innovation – a stroke of genius – was to fuse his three quatrains together, so that, instead of having separate rhymes (i.e. abab cdcd efef), the first rhyme of the new quatrain picks up on the last rhyme of the previous one. This links the argument together more neatly, and shows that, whatever his flaws as a sonneteer, Spenser was a master of rhyme – a fact that The Faerie Queene abundantly demonstrates.