Two of the multiple things that set Spenser apart as a great writer among his peers, like Shakespeare and Jonson, and in contemporary times are his genius for allegory and his uncanny ability to incorporate calendrical (pertaining to the calendar) and astronomical (pertaining to astronomy) elements in his poetry. A brilliant example of the first is The Faerie Queene while an equally brilliant example of the second is Epithalamion. The Faerie Queene has been well lauded for the detail and excellence of its allegorical representations. Spenser uses characters, like the Red Cross Knight--a religious crusader--to uncover and discussion religious and political truths of his day. He also pays a noble and great tribute to Queen Elizabeth by incorporating her greatness into his allegory in the character of the Faerie Queene:
That greatest Gloriana to him gave, (20)
That greatest Glorious Queene of Faerie lond,
To winne him worship, and her grace to have,
Which of all earthly things he most did crave;
Epithalamion, once thought by critics to be unrelated to Spenser's Amoretti sonnet collection, is now recognized as the continuation, indeed the culmination, of the great love chronicled in the Amoretti as Spenser sought to win the love of the younger and higher born Elizabeth Boyle. Epithalamion is exceptionally great for the way the underlying structure progresses through the calendar cycles and astronomical cycles. There are 23 stanzas and a final envoy for the 24 hours in a day.
According to Hieatt, the stanzas of 18 lines each correspond to Midsummer's Day, the summer solstice (St. Barnaby's feast day): "This day the sun is in his chiefest height, / With Barnaby the bright" (470-471). In a mock lament, Spenser alludes to the winter solstice (St. Lucy's feast day) saying the longer night is surrounded by the symbols of the death of nature in winter: "'Tis the year's midnight, ... / Lucy's [with] scarce seven hours ... / The sun is spent" (69-71) (Edgecombe). There are 365 long lines for the days of a year. There are 68 short lines for weeks plus months plus seasons of the year (52 + 12 + 4 = 68). When considered with the amazing structure of the echo refrain with its 17 variations (John B. Lord), Spenser's Epithalamion is a stellar tribute to his greatness as a writer and poet.
An additional point is Spenser's mastery of language. He wrote in a modified imitation of Middle English so that the language of his works has a much older feeling to it although Spenser was a contemporary of Shakespeare and Sir Philip Sidney. Spenser also used the smallest components of language, the individual sounds (the phonemes) to create mood. With a simple change of dominant sounds, for example from /p, t, d/ to /s, m, n/ sounds, Spenser can calm a heightening tension, set a scene of soothing tranquility--or by reversing the example, Spenser can instantly move the reader from tranquility to suspense and tension. In the quote below from The Faerie Queene, note the change--and its effect--from dominant /f, l, w/ to a newly dominant /f, g, d, t/:
Therefore I read beware. Fly fly (quoth then (116)
The fearefull Dwarfe) this is no place for living men.
But full of fire and greedy hardiment,
The youthfull knight could not for ought be staide,
But forth unto the darksome hole he went, (121)
And looked in: his glistring armor made
A litle glooming light, much like a shade,
By which he saw the ugly monster plaine, ….