Manuscript Letter Signed to the Commissioners of the Admiralty, Algernon Sidney, Sir Robert Honywood, and Thomas Boone

An exceptionally scarce 1659 Commonwealth diplomatic letter signed by the famed republican philosopher and martyr Algernon Sidney, alongside fellow plenipotentiaries Sir Robert Honywood and Thomas Boone. Dispatched from Copenhagen to the Commissioners of the Admiralty at Whitehall, the manuscript authorises emergency victualling funds for two Parliamentarian warships—the Langport and the Maydstone—stationed in the Baltic during the Dano-Swedish War.

Preserved in Near Fine condition with its integral address leaf, contemporary docketing, and red wax seal remnant, the document is housed in a 19th-century collector's booklet featuring an 1833 steel-engraved portrait of Sidney, printed biographical leaf, and a neat manuscript fair copy.

Publication: Copenhagen, Denmark, by Algernon Sidney, Sir Robert Honywood, and Thomas Boone, 1659.

Formatting: Folio manuscript bifolium, pp. [4], housed within a 19th-century paper collector's booklet containing an engraved portrait plate, tissue guard, printed biographical leaf, and loose manuscript fair-copy transcript.

Condition Report: Near Fine. Viewed in the context of a nearly 400-year-old state dispatch, this manuscript survives in exceptional, collector-grade condition, preserved by its long-term housing within a protective 19th-century bespoke booklet. The original 17th-century laid paper remains remarkably supple and crisp, displaying only light, uniform age-toning and negligible spotting, entirely free from structural brittleness or damp-staining. The brown ink across both the main body and the three plenipotentiary signatures is dark, bold, and fully legible, with zero corrosive iron-gall ink burn or bleed-through. The original postal folds remain strong and supple without splitting or separation along the creases, while the integral outer address leaf retains a substantial, well-preserved portion of its original red wax seal alongside crisp contemporary docketing. The housing booklet—comprising stiffened paper wraps, an 1833 steel-engraved portrait with its tissue guard, mounted biographical text, and a neat 19th-century fair-copy transcript—shows only light handling wear and mild marginal foxing to the portrait plate, keeping the 1659 manuscript centrepiece in outstanding order. A premier centerpiece for collectors of 17th-century British political history, naval archives, and early democratic thought.

Catalogue Note: Dated 12 September 1659 from Copenhagen, this original Commonwealth naval dispatch is signed by the three English Plenipotentiaries to the Sound—"Al: Sydney" (Algernon Sidney), "Robt: Honywood" (Sir Robert Honywood), and "Tho: Boone" (Thomas Boone), and addressed on the integral verso to "The Right Honble the Comissrs of the Admty att Whitehall". Written on behalf of the English Republic, the letter authorises urgent funds to provision ("victuals") two warships "in the service of the Parliament" whose deployment in Danish waters had been extended: the 50-gun Langport, commanded by Captain Copping (allocated up to £120 sterling), and the 40-gun Maydstone, commanded by Captain Penrose (allocated up to £80 sterling). The plenipotentiaries confirm they have instructed the captains to draw these sums from Elsinore merchant Mr. Goffe, and formally request the Admiralty Commissioners to order the Treasurer of the Navy to honour the resulting bills signed by the captains or their pursers.

Penned during the pivotal final months of the Interregnum under the restored Rump Parliament, the dispatch offers primary-source documentation of the English fleet's intervention in the Baltic Sea to safeguard maritime trade and mediate the Dano-Swedish War. Its foremost appeal lies in the bold autograph of lead signatory Algernon Sidney (1623–1683), the celebrated republican political theorist whose Discourses Concerning Government profoundly influenced modern constitutional and democratic thought. Because Sidney spent much of his life in continental exile or imprisoned prior to his 1683 execution for treason following the Rye House Plot, his authentic signature is exceptionally scarce on the open market.

The manuscript is presented inside a 19th-century stiffened paper collector's booklet assembled to contextualise and protect the letter. Opening the booklet reveals a fine steel-engraved portrait of Sidney by J. Cochran (published 1 August 1833 by Harding & Lepard after the original painting in the collection of Sir John Shelley Sidney, Bart.), facing the corresponding printed biographical text leaf from Edmund Lodge's Portraits of Illustrious Personages of Great Britain beneath a protective tissue guard. The original 1659 bifolium letter (complete with its integral address panel, red wax seal remnant, and contemporary docketing reading "12 Septemb. 1659 / Plenipotentiaries from Coppenhaguen") is housed within, accompanied by a loose, highly legible 19th-century manuscript transcript penned in blue ink on lined paper.