Celtic literature is the body of literature written in one of the Celtic languages, or else it may popularly refer to literature written in other languages which is based on the traditional narratives found in early Celtic literature. Background In the strictly academic context of Celtic studies, the term Celtic literature is used by Celticists to denote any number of bodies of literature written in a Celtic language, encompassing the Irish, Welsh, Cornish, Manx, Scottish Gaelic and Breton languages in either their modern or earlier forms. Alternatively, the term is often used in a popular context to refer to literature which is written in a non-Celtic language, but originates nonetheless from the Celtic nations or else displays subjects or themes identified as "Celtic". Examples of these literatures include the medieval Arthurian romances written in the French language, which drew heavily from Celtic sources, or in a modern context literature in the English language by writers of Irish, Welsh, Cornish, Manx, Scottish or Breton extraction. Literature in Scots and Ulster Scots may also be included within the concept. In this broader sense, the applicability of the term "Celtic literature" can vary as widely as the use of the term "Celt" itself. For information on the development of particular national literatures, see: Irish literature, Scottish literature, Welsh literature, Literature in Cornish, Breton literature and Manx literature. Revival literature in non-Celtic languages The Gaelic Revival reintroduced Celtic themes into modern literature. The concept of Celticity encouraged cross-fertilisation between Celtic cultures. There have been modern texts based around Celtic literature. Bernard Cornwell writes about the Arthurian legends in his series The Warlord Chronicles. Other writers of Celtic literature in English include Dylan Thomas and Sian James. Themes from Celtic Literature within Arthurian Romances Within many Arthurian texts one can see the influence of Celtic literature and folklore. Examples of Arthurian legends with these components are Marie de France's Lanval, the tale of Sir Gawain and the Green Knight, and in Perceval, The Story of the Grail. In his work "Celtic Elements in Lavenal and Graelent," Cross claims that Lanval is a medieval narrative called, "Brenton Lays" otherwise known as works that claim descent from Celtic tradition. Sir Gawain and the Green Knight is said to contain traditions from early Irish Lore, such as the Beheading test. In addition to Sir Gawain and the Green Knight and Lanval, Perceval, The Story of the Grail contains