Renowned Tolkien scholar Tom Shippey and top Tolkien artist John Howe have signed on to Amazon's Lord of the Rings prequel series.
Shippey is the author of The Road to Middle-earth (1982), a relatively early and influential work of Tolkien scholarship, and has collaborated with Harry Harrison on science fiction short stories and a novel trilogy. Shippey is also a noted retired professor of Middle and Old English literature, and taught and worked at Oxford. He met Tolkien shortly before the author's death. Shippey is noted particular for his view that Tolkien was a "traumatised war author" whose experiences in WWI shaped his outlook and fiction. Shippey worked on Peter Jackson's Lord of the Rings movie trilogy by advising on the lore and dialects of the fictional languages. Shippey's work was quoted by Christopher Tolkien in his History of Middle-earth series.
John Howe is a famed Tolkien artist, responsible for illustrating many of Tolkien's works over the years. Howe is one of the unofficial trifecta of top Tolkien artists, along with Alan Lee and Ted Nasmith. He has also illustrated the works of many other major fantasy authors, including Jack Vance, George R.R. Martin and Robin Hobb. Howe worked with Alan Lee as an artist on the Lord of the Rings movie trilogy, with several key designs (most notably the tower of Orthanc in Isengard) based directly on his earlier Tolkien illustrations. Howe is also a keen military reenactor, with specialised knowledge of armour design and construction, in which capacity he also worked on the movie trilogy.
Shippey and Howe's work has already been seen by fans: Howe drew the maps Amazon used in their viral marketing campaign in February and March this year, culminating in the revelation that the first season (at least) will be set in the Second Age of Middle-earth, whilst Shippey advised on lore and fine details. In particular, it is believed that Shippey provided information on how the coastlines of Middle-earth changed as a result of the sinking of Numenor (information which was written by Tolkien, but buried very deep in his notes).
Their role in the full series will presumably be in the field of continuing to advise on the lore, and hopefully in Howe's case contribute some concept artwork.