The Langham letter, published by 1580, is a significant source for the entertainments of the Elizabethan period in England. Dated from Worcester on 20 August 1575, and titled A letter: whearin, part of the entertainment vntoo the Queenz Maiesty, at Killingwoorth Castl, in Warwik Sheer in this soomerz progress 1575. iz signified: from a freend officer attendant in the coourt, vntoo hiz freend a citizen, and merchaunt of London, it describes the summer 1575 entertainment of Elizabeth I of England by Robert Dudley, 1st Earl of Leicester at Kenilworth Castle. It is addressed to Humfrey Martyn, the son of Sir Roger Martyn, a master of the Mercers' Company.
The authorship of the letter was ascribed to Robert Langham (c. 1535-1579/80), a mercer and keeper of the privy council chamber, based on the author's references to himself in the letter as "Lanham" or "Laneham", "Langham", "Ro. La.", and "R. L. Gent. Mercer", and other biographical details, such as his self-description as a "Merchauntaventurer, and Clark of the Councell chamber doore", for which office he writes that he obtained through the patronage of Leicester. Council records confirm that he was paid £10 each April from 1573 to 1579 as keeper of the council chamber.
The letter's editor, R. J. P. Kuin, argues that it is an authentic account by Langham, but others think it was written by William Patten as a joke at Langham's expense, a view which has been accepted by some authorities. The argument for Patten's authorship is based on similarities of form, style, subject matter, and phraseology common to the letter and Patten's acknowledged work and the close resemblance between his known hand and that which appears in two annotated copies of the letter. In addition, Patten himself witnessed the Kenilworth festivities and contributed some Latin verses to welcome the queen. Edward de Vere, the 17th Earl of Oxford, has also been put forth as the author as one of the arguments for his authorship of the works of William Shakespeare, although he was on the European continent from January or February 1575 to April 1576 and was not present at the festival.
The work was reissued at Warwick in 1784, and was reprinted in John Nichols's Progresses of Queen Elizabeth. Sir Walter Scott quoted from it in his novel Kenilworth (1821), leading to the republication of the Letter in London the same year. Subsequent reprints were in George Adlard's Amye Robsart (1870), in the Rev. Edward Hadarezer Knowles's Castle of Kenilworth (1871), and in the publications of the Ballad Society (ed. Furnivall), 1871.
- Lee, Sidney (1892). "Laneham, Robert". In Lee, Sidney. Dictionary of National Biography 32. London: Smith, Elder & Co.
- Woudhuysen, H. R. "Langham, Robert (c.1535–1579/80)". Oxford Dictionary of National Biography (online ed.). Oxford University Press. doi:10.1093/ref:odnb/16002. (Subscription or UK public library membership required.)
- Stähler, Axel. “Imagining the Illusive/Elusive? Printed Accounts of Elizabethan Festials” in Queen Elizabeth I: Past and Present, Christa Jansohn, ed., Studien zur englischen Literatur 19. Müenster: Lit Verlag, 2004, pp. 61-88; n. 6 p. 75.
- Dictionary of National Biography, Laneham, Robert (fl. 1575), writer on the Kenilworth festivities of 1575, by Sidney Lee. Published 1892.
- Langham, Robert. A Letter. R. J. P. Kuin, ed. E. J. Brill: Leiden, The Netherlands, 1983.
- Logan, Sandra. Text/events in early modern England: Poetics of History. Ashgate: Aldershot, Hants; Burlington, VT. (2007)