For your consideration is an exceptionally important and unusually well-documented Irish official Crown-office seal matrix of Strangford, County Down, dated 1618, executed during the reign of King James VI and I (16031625). Monumental for a working administrative seal, the matrix measures approximately 3.0 by 3.5 inches across the face and weighs approximately 410 grams, its dense dark stone body cut into a substantial faceted form suited to repeated institutional use. The intaglio face bears the crowned harp of Ireland within a shield beneath an arched royal crown, surrounded by a Latin legend prominently incorporating STRANGFORD and the abbreviated formula SIGI OFFI, most plausibly identifying a sigillum officii, or seal of office. The reverse is contemporaneously carved within a double-bordered hexagonal cartouche ANO / T R / 1618, with a large interlaced T.R. monogram and floral rosettes. A lightly scratched E.M. on one facet is of different character and is most plausibly a later ownership or inventory mark.

The matrix is best understood as an official Crown administrative seal connected with the customs, revenue, or port administration of Strangford, rather than as a private signet or family seal. Strangford was an active maritime and customs centre in the Lecale district, and surviving early seventeenth-century port-book material confirms the operation of customs administration there immediately before the matrix was made. Its substantial scale, crowned national emblem, office formula, and absence of personal heraldic bearings are entirely consistent with an institutional seal retained by an office and used repeatedly to authenticate formal documentation. Its probable function was therefore the sealing of cockets, warrants, certificates, clearances, fiscal instruments, or related port and customs papers issued under Crown authority.

Of exceptional significance is the survival of an independent nineteenth-century visual record of this very matrix in the National Library of Ireland. William Frazers Sketch books of Irish antiquities preserve four corresponding studies of the Strangford objecttwo of the crowned-harp working face and two of the distinctive T.R. / 1618 reversecatalogued as PD 1975 TX 11 (87). The correspondence is highly specific in crown, harp, legend disposition, faceted form, reverse cartouche, monogram, rosettes, and date, identifying the surviving matrix with the antiquarian object recorded in the Library. The same volume preserves an associated four-page letter from Rev. F. J. Clay Moran to Baron Ashbourne, catalogued as PD 1975 TX 11 (87a), concerning a seal possibly attributed to Sir William Strangford in 1618. That antiquarian attribution remains unresolved and should not presently be treated as a secure personal identification, but the letter establishes that the matrix was the subject of specific historical investigation in the nineteenth century. The NLI further records Frazers drawings as copies after earlier material associated with John Windele and F. J. Clay Moran, indicating that documentary knowledge of the seal predates Frazers own late nineteenth-century sketchbook.

The survival of a dated 1618 Irish Crown-office matrix of this extraordinary scale, together with detailed nineteenth-century studies of both its working face and reverse preserved in Irelands national collection, is highly exceptional. The object can be securely located at Strangford under James I, its official function is strongly indicated by its crowned harp and sigillum officii formula, and its physical appearance was independently documented long before its present ownership. Pending recovery of the complete peripheral legend and definitive identification of the reverse initials T.R., it should be catalogued as a 1618 Strangford Crown customs/revenue or port-office seal matrix, an important surviving instrument of early Stuart government in Ireland and a museum-level artifact of seventeenth-century Irish administrative, maritime, and institutional history.