The collection of his official correspondence published in 1676 is less remarkable for the quantity of work than the quality.
The letters are not very numerous, but are mostly written on occasions requiring a choice dignity of expression.

"The uniformly Miltonic style of the greater letters," says Professor Masson, "utterly precludes the idea that Milton was only the translator of drafts furnished him." We seem to see him sitting down to dictate, weighing out the fine gold of his Latin sentences to the stately accompaniment, it may be, of his chamber-organ.

War is declared against the Dutch; the Spanish ambassador is reproved for his protraction of business; the Grand Duke of Tuscany is warmly thanked for protecting English ships in the harbour of Leghorn; the French king is admonished to indemnify English merchants for wrongful seizure; the Protestant Swiss cantons are encouraged to fight for their religion; the King of Sweden is felicitated on the birth of a son and heir, and on the Treaty of Roeskilde; the King of Portugal is pressed to use more diligence in investigating the attempted assassination of the English minister; an ambassador is accredited to Russia; Mazarin is congratulated on the capture of Dunkirk.

Of all his letters, none can have stirred Milton's personal feelings so deeply as the epistle of remonstrance to the Duke of Savoy on the atrocious massacre of the Vaudois Protestants (1655); but the document is dignified and measured in tone.

His emotion found relief in his greatest sonnet; blending, as Wordsworth implies, trumpet notes with his habitual organ-music; the most memorable example in our language of the fire and passion which may inspire a poetical form which some have deemed only fit to celebrate a "mistress's eyebrow"[4]:-- "Avenge, O Lord, Thy slaughtered saints, whose bones Lie scattered on the Alpine mountains cold; Even them who kept Thy truth so pure of old, When all our fathers worshipped stocks and stones.
Forget not: in Thy book record their groans Who were Thy sheep, and in their ancient fold Slain by the bloody Piemontese that rolled Mother with infant down the rocks.