Nathaniel Bacon, An Historical Discourse of the Uniformity of the Government of England (London, 1647).
Nathaniel Bacon, The Continuation of an Historical Discourse of the Government of England until the End of the Reigne of Queene Elizabeth with a Preface, being a Vindication of the Ancient Way of Parliaments in England (London, 1651).
In my copy, these companion volumes are bound together in a modern leather binding.
Published in 1647, Bacon's An Historical Discourse is motivated by anti-royalist ideology, and is intended to justify the Long Parliament's war against Charles I. For this purpose, Bacon turns to the medieval past, arguing that the Anglo-Saxons were free people governed by laws made by themselves, that they made a contract with their king whom they would obey as long as he governed properly in accordance with the laws, that the king who failed to govern properly resigned and let his subjects replace himself with another, and that the Anglo-Saxons were governed by a grand assembly or parliament. In chapter 43 'An Epilogue to the Saxon government' (pp. 111-12), Bacon concludes as follows:
The Saxon Commonweale was a building of greatest strength downward even to the foundation, arched together both for peace and warre, That by the law of Decenners, wherein Justice was the bond, this by their armies gathered, not by promiscuous flocking of people, but by orderly concurrance of families, kindreds, and Decenners, all choosing their own leaders; and so honour, love, and trust conspired together to leave no mans life in danger, nor death unrevenged. It was a beautifull composure, mutually dependant in every part from the Crown to teh cloune, the Magistrates being all choice men, and the King the choicest of chosen; election being the birth of esteem, and that of merit; this bred love and mutuall trust, which made them as corner-stones, pointed forward to breake the wave of danger; nor was other reward expected by the great men, but honour and admiration, which commonly brought a return of acts of renown. (p. 112)
In arguing all these, Bacon bases himself upon Modus tenendi parliamentum, the Mirror of Justices, and the laws of Edward the Confessor. He claims that the same remained valid after the Norman Conquest and later, up to the Stuart period, since the laws of Edward the Confessor kept being confirmed by the kings in coronation charters, coronation oaths, Magna Carta and other documents.
Because of the anti-royal ideology, some regarded it as a dangerous book that could stir up a rebellion, but it was quite influential and was reprinted in 1672, 1682, 1689, 1739, and 1750.
Bacon published a continuation of An Historical Discourse in 1651 to put some more emphasis upon 'the continuity of an elective and contractual monarchy and a parliament which oversaw its proper functioning' (quoted from Greenberg, 'Bacon, Nathaniel'). He concludes the continuation with the following words:
I now conclude, as I found this Nation a Common-Wealth, so I leave it, and so may it be for ever; and so will it be, if we may attain the happinesse of our Fore-Fathers the ancient Saxons, ... (pp. 306-7)
For the life and works of Nathaniel Bacon, see Janelle Greenberg, 'Bacon, Nathaniel' in the Oxford Dictionary of National Biography.