Henry Hexham (1585?–1650?) was an English military writer.
Hexham was born in Holland, Lincolnshire. His mother appears to have been a sister of Jerome Heydon, merchant, of London, who was probably related to Sir Christopher Heydon. The cousin, John Heydon, to whom Hexham dedicates his Appendix of Lawes, has been identified with Sir John Heydon (died 1653), Sir Christopher's son, and Sir Christopher's daughter Frances married Philip Vincent, who has commendatory verses prefixed to Hexham's translation of Mercator's Atlas.
Hexham was in early youth attached as a page to the service of Sir Francis Vere; he was with Vere throughout the siege of Ostend in 1601, and his narrative of that event is printed at the end of Sir Francis Vere's Commentaries (1657). Hexham seems to have served with Sir Francis until his return to England in 1606 and to have remained in the Low Countries, possibly in one of the towns garrisoned by the English; he was personally acquainted with Prince Maurice of Nassau and his brother, Frederick Henry. In 1611 he published a Dutch translation of The Highway to Heaven, by Thomas Tuke, under the title De Konincklicke wech tot den Hemel … (Dordrecht); and in 1623 appeared A Tongue Combat lately happening between two English Souldiers … the one going to serve the King of Spain, the other to serve the States Generall (London, 1623). When Sir Horace Vere in 1625 went to the relief of Breda, Hexham was quartermaster to Vere's regiment, and he occupied a similar position under Vere during the siege of 's-Hertogenbosch in 1629, at the capture of Venlo, Roermond, and Strale, and the siege of Maastricht in 1631–2.
After Vere's death Hexham became quartermaster to the regiment of George Goring, with whom he served at the siege of Breda in 1637. In 1640 he was in England, and on 27 July he received a pass on going to Holland on private business. On 23 July 1641 Edward Conway, 2nd Viscount Conway wrote to Secretary Edward Nicholas that he had known Hexham as long as he could remember, and was sure that Hexham was a good Protestant and would take the oath of allegiance and supremacy, which he did four days later. Hexham, however, took no part in the civil wars in England; he returned to Holland before 1642, and remained there in the Dutch service and busy with his literary work. His English-Dutch Dictionary has a preface dated Rotterdam, 21 September 1647, and he probably died about 1650.
Hexham's most substantial work is his edition of Mercator's 'Atlas;' this was a translation into English of the edition by Jodocus Hondius, but Hexham made additions of his own, and was further assisted by Hondius's son Henry. The preface is dated Amsterdam, 1 January 1636 'stilo veteri,' and the work is dedicated by Hexham to Charles I; it was published at Amsterdam in 1636–7 (2 vols.), contains many maps and coloured plates, and is the standard edition of Mercator. Another important work by Hexham was his Copious English and Nether-duytch Dictionarie … as also a compendious grammar for the instruction of the learner. The English-Dutch part was published at Rotterdam (1648), and dedicated by Hexham to his friend Sir Bartholomew van Vouw, knt.; the Dutch-English part was not published until 1658 (Rotterdam), and Hexham's preface has no date. He claims that his is the first dictionary of the kind, and a second edition was published by Daniel Manly, the Dutch-English part in 1672, and the English-Dutch part in 1675 (both Rotterdam, 4to).
Hexham's other works relate to military history, dealing with events in which he himself took part. They are:
- ‘A Historicall Relation of the Famous Siege of the Busse and the Surprising of Wesell …,’ Delft, 1630, dedicated to the merchants adventurers at Delft; a Dutch edition was published in the same year.
- ‘A Journall of the taking of Venlo, Roermont, Strale, the memorable Siege of Mastricht, the towne and castle of Limbruch … anno 1632,’ Delft, 1633; dedicated to his kinsman Francis Morrice, clerk of the king's ordnance, who had married his uncle Jerome Heydon's widow; a Dutch edition was published at 's Gravenhage (1633).
- ‘The Principles of the Art Militarie practised in the Warres of the United Netherlands,’ London, 1637; dedicated on 5 September 1637 to Henry Rich, 1st Earl of Holland. A second and enlarged edition was published in three parts: the first two at Delft in 1642, and the third at Rotterdam in 1643; Dutch editions appeared at the same time, dedicated to William of Orange and Charles I Louis, Elector Palatine.
- 'A True and Briefe Relation of the famous Siege of Breda,' Delft, 1637, dedicated to the Earl of Holland; a Dutch edition was published at The Hague (1638).
- 'An Appendix of the Quarter for the ransoming of Officers … together with the Lawes and Articles of Marshall discipline enacted on the States side,' Delft, 1637; another edition, The Hague, 1643.
- 'The Art of Fortification … by Samvell Marolois … augmented by Albert Girard … and translated by Henry Hexham,' Amsterdam, 1638; translated from Samuel Marolois, it is dedicated to Henry Vane the elder.
- 'A True Relation of the Battell of Nieupoort,' Delft, 1641.
- 'An Appendix of Lawes, Articles, and Ordinances established for Marshall Discipline in the service of the … States Generall … translated out of Dutch into English,' The Hague, 1643; dedicated to Hexham's cousins, John Heydon and John Harvey. In the preface, dated Delft, 30 January 1643 'stilo novo,' Hexham says he wishes to prevent the pillage committed on both sides during the civil wars by showing the means taken by the Dutch to check it; he also remarks that he had served forty-two years in the wars and had never been wounded.
- "Hexham, Henry 1585?–1650?". WorldCat. Retrieved 6 April 2017.
- Lee, Sidney, ed. (1901). "Hexham, Henry". Dictionary of National Biography, 1901 supplement. London: Smith, Elder & Co.