Christopher Tolkien
Christopher John Reuel Tolkien, was born on November 21, 1924, to John Ronald Reuel Tolkien, and Edith Mary Tolkien (January 21, 1889-November 29, 1971), their third and youngest son. He has taught at Oxford University, where his father was a professor, and is sole literary executor of his fathers works, which he edits and provides commentary on. He drew the original maps for his father's The Lord of the Rings, which he signed C. J. R. T. The J. stands for John, a baptismal name that he does not ordinarily use. [Sources: Wikipedia, back flap(s) of his publications.]
Works (12)

Morgoth's Ring
1993

The peoples of Middle-Earth
1996

The War of the Ring
1990

The Shaping of Middle-Earth
1986

The Treason of Isengard
1989

Sauron Defeated
1992

The war of the jewels
1994

The book of lost tales
1983

The History of Middle-earth
August 5, 2002

Pictures
November 1, 1979

The Complete History of Middle-Earth
January 6, 2003

The History of Middle-Earth: Index