The Correspondence of Isaac Vossius

Primary Contributors:

Robin Buning

Isaac Vossius (1618–1689)

The Dutch philologist, manuscript collector, and polymath Isaac Vossius was born in Leiden in 1618, the eighth of nine children of the famous humanist scholar Gerardus Joannes Vossius and his second wife Elisabeth Junius. Isaac was schooled at home and studied Arabic briefly at Leiden, before returning to his family for reasons of health and conducting his philological studies from there. He remained in close contact with the Leiden professor Claude de Saumaise, who continued to coach him, and various family friends and pupils of Gerardus Joannes — such as Johann Frederick Gronovius and George Rataller Doublet — became his lifelong friends.

A Grand Tour made between 1641 and 1644 took Vossius to England, France, and Italy. His travelling companion in England and France was John Albert Huswedel, a nephew of Gerardus Joannes’s amanuensis John Christoph Huswedel. Vossius visited libraries and made contacts with famous scholars: in Cambridge he met, among others, James Ussher; in Rouen Claude Sarrau; in Paris Hugo de Groot, the brothers Pierre and Jacques Dupuy (who formed the centre of the intellectual circle at Paris later known as the Cabinet Dupuy), Ismael Boulliau, Henri de Valois, Gilles Ménage, Melchisédech Thévenot, and Denis Pétau; in Padua Gaspare Scioppio. On his way north from Italy he stayed for a year with De Groot in Paris, working as his secretary in succession to Coenraad van Beuningen, who became one of Vossius’s closest friends. This journey laid the foundation for Vossius’s manuscript collection and many of his later epistolary contacts and scholarly activities.

Back in the United Provinces, Isaac succeeded his brother Matthaeus, after the latter’s death in 1646, as city librarian of Amsterdam, a position he held for two years, and he was appointed as historiographer of the States of Holland and Zeeland.

In 1649 he travelled to Stockholm to work as tutor to Christina of Sweden, accompanied by the Harderwijk professor of history and Greek Cornelius Tollius, a former amanuensis of his father’s, who now served as Isaac’s amanuensis. That same year Gerardus Joannes died and Isaac sold his father’s collection of books to Christina on condition that he would be appointed court librarian. To make purchases for the library he travelled around Europe in the company of Nicolaas Heinsius. Following a quarrel with his former teacher Saumaise, who had come to Sweden at the invitation of Christina, Vossius’s position at the Swedish court was weakened. After Christina’s abdication in 1654, he accompanied her to Antwerp, and, as outstanding back pay, he received from her a large number of books and manuscripts, including the famous Codex Argenteus.

On his return to The Hague in 1655, Vossius moved in with his mother and his uncle Franciscus Junius the younger. In 1663 Vossius was awarded an annuity by Louis XIV of France, at which point he was living more or less permanently in Paris, where he attended Thévenot’s académie, one of the precursors of the Académie Royale des Sciences. One of the other people he met in Paris was the writer Charles de Saint-Évremond. In 1666 Vossius moved back to the United Provinces but, in 1670, when the States of Holland and Zeeland refused to pay his salary as official historiographer (on the basis that he had not written anything), Vossius moved to England where he was installed as secular canon of St George’s Chapel in Windsor in 1673, receiving a prebend, which enabled him to devote himself to collecting books and manuscripts. Within a couple of years, through Saint-Évremond, who had taken refuge in England, and Hortense Mancini, a mistress of Charles II, Vossius gained entry to London’s aristocratic circles. In 1679 the notorious historical sexologist Adrian Beverland joined Vossius in Windsor to serve as his secretary.

Vossius was engaged in diverse fields of scholarship. He produced editions and commentaries on classical and contemporary authors, conducted historical studies, and was regarded as an important scholar in ancient geography, patristics, and chronology. He was a religious libertine and caused controversy with his treatises on the age of the earth, which, together with other polemical writings of his, were reprinted in De septuaginta interpretibus eorumque tralatione et chronologia dissertationes (The Hague, 1661). Towards the end of his life, his interests shifted to mathematics and natural philosophy.

After his death in 1689, his library, which was counted among the best private libraries in the world and which was purchased by Leiden University, consisted of c.4,000 printed books and over 700 manuscripts (the so-called ‘Codices Vossiani’; the 363 Latin codices are available online for subscription on Codices Vossiani Latini Online).

Partners and Additional Contributors

The metadata for Isaac Vossius’s correspondence were collected by ‘Cultures of Knowledge’ Postdoctoral Fellow Robin Buning during research carried out in Special Collections of the University of Amsterdam, in Leiden University Library on a Scaliger Fellowship, and in the Bodleian Library during a COST-funded Short-Term Scientific Mission. Thanks are due to the Scaliger Institute. Leiden and to Cost Action IS1310 ‘Reassembling the Republic of Letters’ for their generous funding of this research.

Thanks are due also to ‘Cultures of Knowledge’ Digital Fellows Lucy Hennings, Callum Seddon, and Katherine Steiner, who helped input a portion of the metadata, as well as the following people and institutions for supplying scans of letters, additional metadata, or other information: Mirjam Agterberg, Tresoar — Frysk Histoarysk en Letterkundich Sintrum; Sander van Bladel, Archief Dordrecht; Bertrand Federinov, Musée royal de Mariemont; Håkan Hallberg, Uppsala University Library; Karen Hollewand; Gerda Huisman, Universiteitsbibliotheek Groningen; Adrie van der Laan, De Bibliotheek Rotterdam; Marion Liebherr, Ludwig-Maximilians-Universität München University Library; Dirk van Miert; John Overholt, Houghton Library, Harvard University; Ida Giovanna Rao, Biblioteca Medicea Laurenziana; Friedrich Simader, Österreichische Nationalbibliothek; Anders Toftgaard, The Royal Library, Copenhagen; Olivier Wagner, Bibliothèque national de France; Hans-Walter Stork, Staats- und Universitätsbibliothek Hamburg; Ilona van Tuinen, Fondation Custodia. Cultures of Knowledge would also like to thank Pim van Bree and Geert Kessels of LAB1100 for their visualization of Vossius’s correspondence network in Nodegoat.

Key Bibliographic Source(s)

Petrus Burman, ed., Sylloges epistolarum a viris illustribus scriptarum tomi quinque (Leiden, 1727).

F.F. Blok and C.S.M. Rademaker, ‘Isaac Vossius’ Grand Tour, 1641–1644. The correspondence between Isaac and his parents’, in LIAS. Journal of Early Modern Intellectual Culture and its Sources, 33 (2006), pp. 151–216.

F.F. Blok and C.S.M. Rademaker, ‘Isaac Vossius’ Grand Tour, 1641–1644. The correspondence between Isaac and his parents. Part II: Isaac Vossius in Italy’, in LIAS. Journal of Early Modern Intellectual Culture and its Sources, 35 (2008), pp. 209–79.

F.F. Blok and C.S.M. Rademaker, ‘Isaac Vossius’ Grand Tour, 1641–1644. The Correspondence between Isaac and his Parents. Part III: Isaac in Paris’, in LIAS. Journal of Early Modern Intellectual Culture and its Sources, 36 (2009), pp. 295–386.


The Isaac Vossius catalogue consists currently of 1,702 letters, which are transmitted in autograph and/or (more than one) manuscript copy and/or printed version. Some letters have up to ten manifestations and the catalogue numbers a total of 4,209 manifestations. Also included are the links to printed editions or manuscripts of 164 letters that are available online.

The letters range in date from 31 January 1632 to 20 January 1689, a month before Vossius’s death. The volume of the correspondence peaks in 1645–53, the period between Vossius’s return from his Grand Tour and the start of his conflict with Saumaise. The catalogue includes hundreds of undated or incompletely dated letters — Vossius was notoriously careless in the dating of his letters. Three books with undated drafts in the Special Collections of the University of Amsterdam, however, can be roughly dated 1647–1651 (hs. VI F 28), 1646–1648, and 1668–1671 (hs. VI F 29), and 1643-1647 (hs. VI F 30).

The list of correspondents numbers 236 names, including most conspicuously his father and the contacts he made during his Grand Tour from 1641 to 1644. Most of the letters are written in Latin (80%) or French (16%); the rest of the correspondence is written in Dutch, Italian, Spanish, Swedish, or Ancient Greek. The content of the letters reflects the diversity of his scholarly activities.

Calendar for the life of Isaac Vossius, compiled by Robin Buning.

Letter from Isaac Vossius to Claude de Saumaise, 28 February 1648. (Image courtesy of Universiteitsbibliotheek Leiden, PAP 7)

Visualization of Vossius’s correspondence network (created by LAB100, with Nodegoat)


The largest collections of Vossius’s correspondence are kept (in descending order of size) by the university libraries of Amsterdam (1,385 letters), Leiden (1,125 letters), and Oxford (629 letters). The Leiden and Oxford collections for large parts consist of copies made from the Amsterdam collection with shelfmarks hs. III E 8–10, containing 805 letters. The four volumes MSS D’Orville 468–71 in Oxford, containing 597 letters, were copied by Jacques Philippe D’Orville (1696–1751) from the library of the Remonstrant Church in Amsterdam (which was incorporated into Amsterdam University Library in 1878), in which city D’Orville was professor of history, rhetoric, and Greek. They were bought by the Bodleian Library in 1805. D’Orville omitted, however, to copy most of the French letters. D’Orville’s successor Petrus Burman the younger (1713–1778) also made copies, which now make up the two volumes BUR F 11–I and II in Leiden University Library, containing 791 letters; these also include the letters in French. The remainder of the letters are kept in libraries, archives and museums in Alkmaar, Copenhagen, Dordrecht, Florence, Groningen, Hamburg, Harvard, Leeuwarden, London, Mariemont, Munich, Münster, Nuremberg, Paris, Rome, The Hague, Uppsala, Utrecht, Venice, and Vienna.

469 of these letters are transmitted also in one or more printed versions. The largest collection of published letters from Vossius’s correspondence is Petrus Burman’s Sylloges epistolarum a viris illustribus scriptarum tomi quinque. This collection contains 109 letters exchanged with Nicolaas Heinsius.

Scope of Catalogue

Sophie Romburg has inferred the existence of several letters from references in other letters, which could not be retrieved. See ‘For My Worthy Freind Mr Franciscus Junius’: An Edition of the Correspondence of Francis Junius F.F. (1591–1677), ed. Sophie van Romburgh (Leiden, 2004), pp. 804, n. 14; 905, n. 12; 904, n. 10; 899, n. 1. These letters are not included in the catalogue.

Jacques George de Chauffepié’s Nouveau dictionnaire historique et critique, pour servir de supplement ou de continuation au dictionnaire historique et critique, de Mr. Pierre Bayle quotes complete letters as well as passages and even single sentences from Isaac Vossius’s letters. Only the completely transcribed letters are included as printed copies in the catalogue. For the rest, see Jacques George de Chauffepié, ed., Nouveau dictionnaire historique et critique, pour servir de supplement ou de continuation au dictionnaire historique et critique, de Mr. Pierre Bayle, 4 vols (Amsterdam/The Hague/Leiden, 1750–56), IV, pp. 457–60 (Cornelius Tollius entry); IV, pp. 460–65 (Jacobus Tollius entry); IV, pp. 614–31 (Isaac Vossius entry).

Of the letters exchanged between Isaac Vossius and Hugo de Groot only the published versions in P. C. Molhuysen, et al., eds, The Correspondence of Hugo Grotius, digital edn (The Hague, October 2009), are included in the catalogue, since this edition mentions all earlier publications.

The collection in Leiden University Library with shelf mark BPL 2366 contains 180 annotated copies of letters from Isaac Vossius’s correspondence with, mainly but not exclusively, Claude Saumaise, as well as related biographical and bibliographical material. This was collected around the turn of the nineteenth century by the Leiden professor of medieval paleography Scato Gocko de Vries with the intention of publishing an edition of Vossius’s correspondence with Saumaise, but the project was never completed. Dirk J.H. ter Horst’s Isaac Vossius en Salmasius, which provides extracts from part of the correspondence between Vossius and Saumaise, draws on this collection.

Further resources

Biographical sources

Blok, F.F., Isaac Vossius and his circle: His life until his farewell to Queen Christina of Sweden, 1618–1655, trans. Cis van Heertum (Groningen: Forsten, 2000).

Isaac Vossius (1618–1689) between science and scholarship, ed. Eric Jorink and Dirk van Miert (Leiden: Brill, 2012).

Henk Nellen and Dirk Imhoff, ‘Isaac Vossius’, Jan Bloemendal and Chris Heesakkers, ed., Bio-bibliografie van Nederlandse Humanisten, online edn DWC/Huygens Instituut KNAW (The Hague, 2009).

Thomas Seccombe, ‘Vossius, Isaac (1618–1689)’, rev. F. F. Blok, Oxford Dictionary of National Biography (Oxford, 2004), online edn (2006).

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