Adam Tolkien
From Tolkien Gateway
Adam Tolkien (born 1969) is the son of Christopher Tolkien, brother to Rachel Tolkien and half brother to Simon Tolkien. He translated into French several works of his grandfather: Pictures by J.R.R. Tolkien (1994), The Book of Lost Tales 1 (1995), and The Book of Lost Tales 2 (1998).
See also:
Interview with Adam Tolkien