English version: "Thayer-Forbes":
Thayer's Life of Beethoven. Revised and edited by Eilliot Forbes. Rev. ed. Prineton Univ. Press, 1967.
Now a two-volume work highly edited from the original five-volume set in German. Very badly in need of revision, but so badly in need that it is a daunting task.
Other important English-language biographies:
Barry Cooper. Beethoven. Oxford: Oxford University Press, 2000.
This new biography replaces Denis Matthews's volume published in 1984 for the Master Musicians series. Cooper combines discussion of Beethoven's life and music, proceeding chronologically in chapters that encompass three to four years of Beethoven's life.
Martin Cooper. Beethoven / The Last Decade 1817-1827. London: Oxford Unv. Press, 1977.
Cooper's survey of Beethoven's life and works is the only full-length study of Beethoven's last decade. It is well-written and perceptive. Part 1 covers the biography; Part 2 covers the music. Appendix A, written by Edward Larkin, is "Beethoven's Medical History"; Appendix B is "A Note on Beethoven's Metronome Markings."
Carl Dahlhaus. Ludwig van Beethoven / Approaches to His Music. Trans. Mary Whittal. Oxford: Clarendon, 1991
As is obvious from the subtitle, Dahlhaus' book is primarily oriented toward a "biography" of the music. However, there is a great deal of general biographical information contained herein, and Dahlhaus is one of the most important musicologists of the 20th century. The book is densly packed with ideas on the context and interpretation of Beethoven's music.
Joseph Kerman and Alan Tyson. The New Grove Beethoven. New York: Norton, 1980.
Reprint and revision of the long article in The New Grove Dictionary of Music and Musicians. Though a dictionary article, this brief biography and account of the composer's works is an invaluable reference guide and an informative survey of Beethoven's life and works. An updated version of the Kerman/Tyson article is available through Oxford Music Online.
William Kinderman. Beethoven. Berkeley: University of California Press, 1995.
This is a study of Beethoven's creative development, so it focuses on Beethoven's music rather than biography.
Lewis Lockwood, Lewis. Beethoven : The Music and the Llife. New York: Norton, 2003.
The primary focus of this biography is Beethoven's music, although no musical examples are printed in the book. Instead, readers must consult the publisher's website.
George Marek. Beethoven / Biography of a Genius. New York: Crowell, 1969.
Marek's biography has long been out of print, but is readily found in used book stores. Though in need of revision, it remains one of the most popular general biographies of the composer for its straightforward prose and rendition of the composer's life.
Anton Schindler. Beethoven As I Knew Him / A Biography by Anton Felix Schindler. Ed. Donald W. MacArdle and trans. Constance S. Jolly. London: Faber and Faber, 1966.
Anton Schindler was Beethoven's secretary for a few years in the 1820s. His first-hand accounts of the composer's life would be invaluable if he was trustworthy. Schindler destroyed many of the conversation books in his possession, forged entries in his own hand in many of the ones that he did not destroy, has been caught in several lies, and sold his Beethoven collection for a state pension. Nonetheless, there is a great deal of information in Schindler's biography which is not available elsewhere.
Marion Scott. Rev. by Jack Westrup. Beethoven. London: Dent, 1974.
This is the volume on the composer in the Master Musician series. A new biography from Barry Cooper is in the works and is due to be published in 2000. Scott's biography was originally written in the 1940s and was revised for the 1974 edition. A standard survey of the life and works.
Maynard Solomon. Beethoven. New York: Schirmer, 1977; 2nd. ed., rev., 1988.
Solomon's biography occupies a central position in Beethoven studies. The approach to Beethoven's life and works is pyschoanalytic, and Solomon's theories have been influential in the field of Beethoven studies. The book contains a chapter which argues that Antonie Brentano was Beethoven's Immortal Beloved. Solomon updates some of the information in his biography in his collection, Beethoven Essays (Harvard Univ. Press, 1988).
David Wyn Jones. The Life of Beethoven. Musical Lives. Cambridge ; New York : Cambridge University Press, 1998
An abbreviated (204 pp.) biography that provides a good introduction to Beethoven's life.
For other Beethoven biographies, search in the Beethoven Gateway in the Category index (search term: biographies) and limit your search to English-language materials if desired.