John Milton was not the only English person of his day to lament the lack of a comprehensive and reliable history of Britain. Nicholas von Maltzahn details contemporary notices of that need, and identifies several attempts, other than Milton's, to address it. His 1991 book, Milton's History of Britain: Republican Historiography in the English Revolution, is the most reliable historical and critical treatment of this monumental project. Milton believed that any nation worthy of note deserved to have its history well recorded in elegant prose. What Livy did for Rome, Milton intended to do for his beloved Britain, especially England. He committed himself to "endevor that which hitherto hath bin needed most, with plain, and lightsom brevity, to relate well and orderly things worth the noting, so as may best instruct and benefit them that read."
Milton's original plan was to begin with the very earliest legends about Britain's beginning, even though he doubted their veracity, and carry the story forward to his present day. And that day was particularly significant for he believed that England early in 1649 was on the brink of an entirely new epoch of unprecedented civil liberty. Though there has been significant debate about the History's dates of composition, I remain convinced by von Maltzahn's conclusion that Milton wrote the first four books between January 30, 1649, when Charles I was executed for treason, and mid-March, when the newly-constituted Council of State invited him to serve as Secretary for Foreign Tongues (von Maltzahn 24-25). This is what Milton claimed in his Second Defense of the English People (1654) and I see no good reason to doubt him. Though Milton resumed work on the History sometime in the mid 1650s, he never completed his project; the History as it was first published in 1670 ends with its account of the Norman conquest in 1066.
Milton's History of Britain presents readers (and editors) with several difficulties. First, it was published more than twenty years after it was begun, under circumstances that resulted in the omission of a portion of Book 3. That portion has come to be known as the "Digression," probably because that is how Milton himself referred to it in its final sentence: "But on these things, and this Parallel, having enough insisted, I return to the story which gave us matter of this Digression." Those circumstances have been considerably clarified by Nicholas von Maltzahn's 1991 book and his subsequent defense of its chief arguments in his 1993 article, "Dating the Digression in History of Britain."
The second difficulty is that the "Digression" exists in two forms. The relatively short portion (about 2500 words) of Book 3 that Milton (probably reluctantly) omitted from the first edition (both printings, 1670 and 1671) first appeared in print in 1681 as a pamphlet, edited by Roger L'Estrange, a staunch and active royalist who served the Restoration court as Licenser and Surveyor of the press from 1663 until 1679 (with one interruption). The title L'Estrange chose for this pamphlet is Mr. John Miltons Character of the Long Parliament and Assembly of Divines. In MDCXLI. Omitted in his other Works, and never before Printed, and very seasonable for these times. L'Estrange published this pamphlet as a form of royalist political propaganda. His brilliant idea was to use "Mr. John Milton's" own words (though he had been dead for seven years) to support the crown's resistance to Parliament's attempts to exclude James, Duke of York from succession to the throne. It was as if he were saying to readers, "See, even the great champion of the republican attack on monarchy, John Milton himself, recognized what a bunch of knaves Members of Parliament can be, especially when they oppose their king." von Maltzahn, who first detected L'Estrange as the pamphlet's editor, also speculates that Milton reluctantly agreed to delete this jeremiad on the corruption of the Long Parliament (called in 1640) and the Assembly of Divines it appointed in 1643 because L'Estrange, acting as press licenser in 1670, censored passages that severely criticized Restoration prelates by comparison with their 5th-century Saxon predecessors. In other words, more was deleted from the 1670-71 first edition than the "Digression." Presumably several pages deemed "too sharp against the Clergy" in the persons of 5th-century bishops were also cut, and have yet to resurface (von Maltzahn, 16). As a result, though the History frequently derides ancient monks, and even early modern Presbyterians, it contains precious few critical remarks about prelates, or prelacy in general.
Late in the 19th Century, the "Digression" surfaced in another form—a manuscript now in the possession of Harvard College Library. This version is two pages longer, on the front end. Presumably L'Estrange, if his manuscript of Book 3 matched this one, saw no need to include those first two pages in his 1681 Character and begins his pamphlet with Milton's comments about "those who say'd most in the late Troubles."
All of this means that when readers come to read Book 3 of the History, they might do well to turn their attention to the manuscript version of the Digression (here designated as Digression: MS) when they come to the words, "from one misery to another" at the close of the second paragraph of that book. I have supplied a link to the manuscript Digression at this very point. It will open in a new window or a new tab, and readers can then return to Book 3 without losing their place. The version of the Digression printed as the Character in 1681 may well be treated as Roger L'Estrange's propagandistic use of Milton's writings in service of a cause Milton would have detested. It is well worth study, but as a separate document.
Why did I not simply run the Digression, in its manuscript form, back into the text of the History? Because I wish this edition to preserve the integrity (if that's the right word in such a case) of the first edition printings of 1670-71. Milton may well have been pressured to omit parts of the work, but he did supervise the publication. In any case, digital technology makes it an easy matter to read the Digression back into Book 3, without losing a sense of the political pressures brought to bear on its publication. The MRR edition follows the 1671 printing of the History since it is the last printing supervised by the author.